[coreboot-gerrit] Patch merged into coreboot/master: nb/intel/sandybridge/northbridge: Initialize uma_memory_base in all cases

the following patch was just integrated into master:
commit 240766af027a6f1f7c854eeea799965e30686ce7
Author: Patrick Rudolph 
Date:   Thu Oct 15 15:33:25 2015 +0200

nb/intel/sandybridge/northbridge: Initialize uma_memory_base in all cases

Issue observed:
    Coreboot stops at: "Not enough MTRRs available!"

Test system:
    * Gigabyte GA-B75M-D3H
    * Intel Pentium CPU G2130
    * ATI Radeon HD4780

Problem description:
    In case the IGD does not claim VGA decode, the code path taken results
    in an integer overflow as uma_memory_base isn't initialized.
    The MTRR assignment will fail, because of invalid memory regions.

Problem solution:
    Properly initialize uma_memory_base to prevent possible integer overflow.

Final testing results:
    The system boots again with IGD not claiming VGA decode.

Change-Id: I025be23b1defb6155469a3eee66569e49a695e7f
    Signed-off-by: Patrick Rudolph 
    Reviewed-on: http://review.coreboot.org/11918
    Tested-by: build bot (Jenkins)
    Reviewed-by: Aaron Durbin 
    Reviewed-by: Nico Huber

See http://review.coreboot.org/11918 for details.

-gerrit