[M44_2403] Add arm64 support to ffmpeg

[M44_2403] Add arm64 support to ffmpeg

We need to regenerate this arm64 support patch in ffmpeg
until ffmpeg supports arm64 architecture in mainstream.

The following commands were executed within arm64 GBS wayland chroot:
$ # enter chroot
$ gbs chroot --root
~/GBS-ROOT-3.0-MOBILE-ARM64-WAYLAND/local/BUILD-ROOTS/scratch.aarch64.0/
$ # copy over src/third_party/ffmpeg to chroot (e.g.: /home/abuild)
$ cd ffmpeg
$ ./chromium/scripts/build_ffmpeg.py linux arm64
$ ./chromium/scripts/copy_config.sh
$ # edit chromium/scripts/generate_gyp.py; add "arm64" to support
platforms.
$ python chromium/scripts/generate_gyp.py
$ edit ffmpeg.gyp; add "asm_sources" to the build
$ # generate the patch against a unchanged ffmpeg copy

This patch referred to http://165.213.202.130/gerrit/#/c/80261

Bug: http://web.sec.samsung.net/bugzilla/show_bug.cgi?id=14159

Reviewed by: Antonio Gomes, joonhwan kwon

Change-Id: Ic7e6b1a8ab9b3976f0cf3fc3eafb2a7d9202708a
Signed-off-by: Youngcheol Kang <ychul.kang@samsung.com>