lenovo/x60: Fix build issue with DO_NATIVE_VGA_INIT

Use the value from hardware for uma_memory_base.

Change-Id: I70351166db6634ef3bca2bf12051ccc3730cab8e
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5893
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/northbridge/intel/i945/gma.c

@@ -64,6 +64,7 @@ static void gma_func0_init(struct device *dev)
 	);
 
 	int i915lightup(u32 physbase, u32 iobase, u32 mmiobase, u32 gfx);
+	u32 uma_memory_base = pci_read_config32(dev, BSM) & ~((1 << 20) - 1);
 	int lightup_ok = i915lightup(uma_memory_base, iobase, mmiobase, graphics_base);
 	if (lightup_ok)
 		gfx_set_init_done(1);