mac80211: compile kconf with host gcc

Fix the building issue setting CC to KERNEL_CC in kernel.mk. The
kernel backports by default uses CC to compile kconf. A new patch is
added to mac80211 to compile kconf with host gcc.

Signed-off-by: Zeyu Dong <dzy201415@gmail.com>
[ refresh patches ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

package/kernel/mac80211/patches/build/004-fix-kconf-compiling.patch

@@ -0,0 +1,47 @@
+--- a/Makefile.real
++++ b/Makefile.real
+@@ -6,6 +6,18 @@ else
+ export BACKPORTS_GIT_TRACKER_DEF=
+ endif
+ 
++ifneq ($(LLVM),)
++ifneq ($(filter %/,$(LLVM)),)
++LLVM_PREFIX := $(LLVM)
++else ifneq ($(filter -%,$(LLVM)),)
++LLVM_SUFFIX := $(LLVM)
++endif
++
++HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
++else
++HOSTCC	= gcc
++endif
++
+ # disable built-in rules for this file
+ .SUFFIXES:
+ 
+@@ -24,21 +36,21 @@ listnewconfig oldaskconfig oldconfig \
+ silentoldconfig olddefconfig oldnoconfig \
+ allnoconfig allyesconfig allmodconfig \
+ alldefconfig randconfig:
+-	@$(MAKE) -C kconf conf
++	@$(MAKE) -C kconf CC=$(HOSTCC) conf
+ 	@./kconf/conf --$@ Kconfig
+ 
+ .PHONY: usedefconfig
+ usedefconfig:
+-	@$(MAKE) -C kconf conf
++	@$(MAKE) -C kconf CC=$(HOSTCC) conf
+ 	@./kconf/conf --defconfig=defconfig Kconfig
+ 
+ .PHONY: savedefconfig
+ savedefconfig:
+-	@$(MAKE) -C kconf conf
++	@$(MAKE) -C kconf CC=$(HOSTCC) conf
+ 	@./kconf/conf --savedefconfig=defconfig Kconfig
+ 
+ defconfig-%::
+-	@$(MAKE) -C kconf conf
++	@$(MAKE) -C kconf CC=$(HOSTCC) conf
+ 	@./kconf/conf --defconfig=defconfigs/$(@:defconfig-%=%) Kconfig
+ 
+ .config: