build: introduce ALT vendor/model/variant

Some devices are produced and sold under different names. To debloat
the buildroot but keeping it complete, new variables are introduced to
handle different namings. Below an example taken from a recent PR[0]

    DEVICE_VENDOR := Arcadyan
    DEVICE_MODEL := ARV4520PW
    DEVICE_ALT0_VENDOR := Vodafone
    DEVICE_ALT0_MODEL := Easybox 800
    DEVICE_ALT1_VENDOR := Airties
    DEVICE_ALT1_MODEL := WAV-281

With this commit the buildroot is extended to take care of up to three
alternative namings. The primary title plus alternatives names (if
defined) are shown in the `make menuconfig` dialog. Selecting on of
devices automatically selects all alternative names as they share the
same profile.

A list of the newly introduced variables:

    DEVICE_ALT0_VENDOR :=
    DEVICE_ALT0_MODEL :=
    DEVICE_ALT0_VARIANT :=
    DEVICE_ALT1_VENDOR :=
    DEVICE_ALT1_MODEL :=
    DEVICE_ALT1_VARIANT :=
    DEVICE_ALT2_VENDOR :=
    DEVICE_ALT2_MODEL :=
    DEVICE_ALT2_VARIANT :=

[0]: https://github.com/openwrt/openwrt/pull/2229/files#diff-b436f01932a18876c27800ba183d95f6R140

Signed-off-by: Paul Spooren <mail@aparcar.org>

include/image.mk

@@ -362,9 +362,21 @@ $(KDIR)/root.%: kernel_prepare
 define Device/InitProfile
   PROFILES := $(PROFILE)
   DEVICE_TITLE = $$(DEVICE_VENDOR) $$(DEVICE_MODEL)$$(if $$(DEVICE_VARIANT), $$(DEVICE_VARIANT))
+  DEVICE_ALT0_TITLE = $$(DEVICE_ALT0_VENDOR) $$(DEVICE_ALT0_MODEL)$$(if $$(DEVICE_ALT0_VARIANT), $$(DEVICE_ALT0_VARIANT))
+  DEVICE_ALT1_TITLE = $$(DEVICE_ALT1_VENDOR) $$(DEVICE_ALT1_MODEL)$$(if $$(DEVICE_ALT1_VARIANT), $$(DEVICE_ALT1_VARIANT))
+  DEVICE_ALT2_TITLE = $$(DEVICE_ALT2_VENDOR) $$(DEVICE_ALT2_MODEL)$$(if $$(DEVICE_ALT2_VARIANT), $$(DEVICE_ALT2_VARIANT))
   DEVICE_VENDOR :=
   DEVICE_MODEL :=
   DEVICE_VARIANT :=
+  DEVICE_ALT0_VENDOR :=
+  DEVICE_ALT0_MODEL :=
+  DEVICE_ALT0_VARIANT :=
+  DEVICE_ALT1_VENDOR :=
+  DEVICE_ALT1_MODEL :=
+  DEVICE_ALT1_VARIANT :=
+  DEVICE_ALT2_VENDOR :=
+  DEVICE_ALT2_MODEL :=
+  DEVICE_ALT2_VARIANT :=
   DEVICE_PACKAGES :=
   DEVICE_DESCRIPTION = Build firmware images for $$(DEVICE_TITLE)
 endef
@@ -426,7 +438,10 @@ DEFAULT_DEVICE_VARS := \
   VID_HDR_OFFSET UBINIZE_OPTS UBINIZE_PARTS MKUBIFS_OPTS DEVICE_DTS \
   DEVICE_DTS_CONFIG DEVICE_DTS_DIR BOARD_NAME UIMAGE_NAME SUPPORTED_DEVICES \
   IMAGE_METADATA KERNEL_ENTRY KERNEL_LOADADDR UBOOT_PATH DEVICE_VENDOR \
-  DEVICE_MODEL DEVICE_VARIANT
+  DEVICE_MODEL DEVICE_VARIANT \
+  DEVICE_ALT0_VENDOR DEVICE_ALT0_MODEL DEVICE_ALT0_VARIANT \
+  DEVICE_ALT1_VENDOR DEVICE_ALT1_MODEL DEVICE_ALT1_VARIANT \
+  DEVICE_ALT2_VENDOR DEVICE_ALT2_MODEL DEVICE_ALT2_VARIANT
 
 define Device/ExportVar
   $(1) : $(2):=$$($(2))
@@ -591,18 +606,35 @@ endef
 
 define Device/DumpInfo
 Target-Profile: DEVICE_$(1)
-Target-Profile-Name: $(DEVICE_TITLE)
+Target-Profile-Name: $(DEVICE_DISPLAY)
 Target-Profile-Packages: $(DEVICE_PACKAGES)
 Target-Profile-hasImageMetadata: $(if $(foreach image,$(IMAGES),$(findstring append-metadata,$(IMAGE/$(image)))),1,0)
 Target-Profile-SupportedDevices: $(SUPPORTED_DEVICES)
 $(if $(DEFAULT),Target-Profile-Default: $(DEFAULT))
 Target-Profile-Description:
 $(DEVICE_DESCRIPTION)
+$(if $(strip $(DEVICE_ALT0_TITLE)),Alternative device titles:
+- $(DEVICE_ALT0_TITLE))
+$(if $(strip $(DEVICE_ALT1_TITLE)),- $(DEVICE_ALT1_TITLE))
+$(if $(strip $(DEVICE_ALT2_TITLE)),- $(DEVICE_ALT2_TITLE))
 @@
 
 endef
 
 define Device/Dump
+ifneq ($$(strip $$(DEVICE_ALT0_TITLE)),)
+DEVICE_DISPLAY = $$(DEVICE_ALT0_TITLE) ($$(DEVICE_TITLE))
+$$(info $$(call Device/DumpInfo,$(1)))
+endif
+ifneq ($$(strip $$(DEVICE_ALT1_TITLE)),)
+DEVICE_DISPLAY = $$(DEVICE_ALT1_TITLE) ($$(DEVICE_TITLE))
+$$(info $$(call Device/DumpInfo,$(1)))
+endif
+ifneq ($$(strip $$(DEVICE_ALT2_TITLE)),)
+DEVICE_DISPLAY = $$(DEVICE_ALT2_TITLE) ($$(DEVICE_TITLE))
+$$(info $$(call Device/DumpInfo,$(1)))
+endif
+DEVICE_DISPLAY = $$(DEVICE_TITLE)
 $$(eval $$(if $$(DEVICE_TITLE),$$(info $$(call Device/DumpInfo,$(1)))))
 endef