Make acpi/ec.c usable in romstage

On X201 to enable EHCI debug you need to go through EC if USB power is
disabled so we need to inclue ec.c.

Change-Id: I8f8b7de639ecaebceaa53cd338136befaeec8214
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/3405
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2 files changed