[LINUXBIOS] Add the CPU_OPT flag to facilitate passing flags into the build
buildROM passes build flags through the CPU_OPT environment variable -
especially -fno-stack-protector for those of us lucky enough to have
Debian/Ubuntu. This adds to the cache_as_ram_auto.inc target
for the GA-2761GXDK so that the resulting cpu0.S is clean.
Signed-off-by: Jordan Crouse <email@example.com>
Acked-by: Ronald G. Minnich <firstname.lastname@example.org>