Fix _OSC

Fix take from http://review.coreboot.org/#/c/3052/

Change-Id: I243527213f3238828c69c7dbff0a02994fd5fa1a
Add some more dsdt fixes from supermicro h8qgi

Change-Id: I6dec7bdae87eae92f7f4f5a1c994cb8ebdc3720f