supermicro/h8scm: Fix Kconfig

Change-Id: I0ecc3c5a26251f248234244bf305d3e13e41b9e9
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/6069
Tested-by: build bot (Jenkins)
Reviewed-by: Idwer Vollering <vidwer@gmail.com>