Adding a attach callback function pointer in case a platform needs
to execute anything before the standard initialization of the sdhci
mem controller.
BUG=b:254092907
BRANCH=None
TEST=emerge-herobrine coreboot
Change-Id: I0f37ec09d083922cad5ecd3c47b184cf3311fe2d
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/72633
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>