libffi: upgrade 3.3 -> 3.4.2

0001-Address-platforms-with-no-__int128-part2.patch
0001-Address-platforms-with-no-__int128.patch
0001-Fixed-missed-ifndef-for-__mips_soft_float.patch
0001-ffi_powerpc.h-fix-build-failure-with-powerpc7.patch
0001-powerpc-fix-build-failure-on-power7-and-older-532.patch
removed since they're included in 3.4.2

refresh 0001-arm-sysv-reverted-clang-VFP-mitigation.patch

License-Updage: Copyright year updated to 2021

Signed-off-by: Zheng Ruoqin <zhengrq.fnst@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>