via/vx900: Remove GFXUMA and use of related global variables

Remove global variables uma_memory_base and uma_memory_size
from builds with via/vx900 northbridge, as these variables can be kept
within the chipset.

Change-Id: I9f8aea4836d81e704eae6a0f2cefc7fd4586b8b8
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5721
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
4 files changed