amd/pi/hudson: Add hudson PM register defines

Clean up hudson PM register accesses with some register defines.

Change-Id: I5ccf27a2463350baec53b7c79fe0fd4ec6c31306
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/19233
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
2 files changed