qemu-binfmt-conf.sh: ignore the OS/ABI field

qemu-binfmt-conf.sh: ignore the OS/ABI field

Most of the binaries have a value of "UNIX - System V" for the OS/ABI.

But cc1 has a value of "UNIX - GNU", and if we don't update the binfmt
mask to ignore the OS/ABI field, gcc fails to execute it:

gcc: error trying to exec '/usr/lib/gcc/m68k-linux-gnu/7/cc1': execv: Exec format error

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180605194725.8585-1-laurent@vivier.eu>