arch/x86: Prevent romcc bootblock from using MMX registers

Platforms with SSE=y or SSE2=y will invoke romcc with -mcpu=k7.
This implicitly enabled romcc to consume MMX registers, if XMM
set was consumed first.

Explicitly tell romcc not to clobber MMX set.

Change-Id: I37f1d6ea01873036712dfbb32bb1dcd5d769e85d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/30392
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

0 files changed, 0 insertions, 0 deletions