amlogic: add video decoder firmwares

Add the firmwares for various video compression standards that are
required to decode video on Amlogic SoCs using hardware acceleration.

They are listed under a custom redistributable license provided by
Amlogic.

Although the filelist is not complete yet (there are a _lot_ of
different codec/SoC combinations), the firmwares added here are
supported and tested with the work-in-progress mainline driver.

The latest submission for the mainline driver can be found here[1], and
the development tree can be found here[2].

[1] https://patchwork.kernel.org/cover/10879959/
[2] https://github.com/Elyotna/linux

Cc: Arden Jin <Arden.Jin@amlogic.com>
Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>

LICENSE.amlogic_vdec

@@ -0,0 +1,15 @@
+---------------------------------------------------------------------
+Amlogic Co., Inc. grants permission to use and redistribute
+aforementioned firmware files for the use with devices containing
+Amlogic chipsets, but not as part of the Linux kernel or in any other
+form which would require these files themselves to be covered by the
+terms of the GNU General Public License or the GNU Lesser General
+Public License.
+
+These firmware files are distributed in the hope that they will be
+useful, but are provided WITHOUT ANY WARRANTY, INCLUDING BUT NOT
+LIMITED TO IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
+PARTICULAR PURPOSE.
+
+Amlogic Contact: Arden Jin <Arden.Jin@amlogic.com>
+---------------------------------------------------------------------

WHENCE

@@ -4399,3 +4399,21 @@ File: microchip/mscc_vsc8574_revb_int8051_29e8.bin
 File: microchip/mscc_vsc8584_revb_int8051_fb48.bin
 
 Licence: Redistributable. See LICENCE.microchip for details
+
+--------------------------------------------------------------------------
+
+Driver: meson-vdec - Amlogic video decoder
+
+File: meson/vdec/g12a_h264.bin
+File: meson/vdec/g12a_vp9.bin
+File: meson/vdec/gxbb_h264.bin
+File: meson/vdec/gxl_h263.bin
+File: meson/vdec/gxl_h264.bin
+File: meson/vdec/gxl_hevc.bin
+File: meson/vdec/gxl_hevc_mmu.bin
+File: meson/vdec/gxl_mjpeg.bin
+File: meson/vdec/gxl_mpeg12.bin
+File: meson/vdec/gxl_mpeg4_5.bin
+File: meson/vdec/gxm_h264.bin
+
+Licence: Redistributable. See LICENSE.amlogic_vdec for details.