Northbridge: i945: Native VGA init: use UMA address

The patch was made by Peter Stuge, I just split it
  and added a commit message.

Change-Id: I4e88c26b70ea8cb249d7613c749b3edc5e3b5e7f
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@no-log.org>
Reviewed-on: http://review.coreboot.org/4000
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
1 file changed