nb/gm45: allow use of 352M preallocated ram for igd

The datasheets on gm45: "Mobile Intel® 4 Series Express Chipset Family"
mention the possibility of having 352M ram preallocated for the
integrated graphic device. This only worked fine if the amount of ram in
the system was 3GB or less. When 4G or more is installed, memory is
remapped to create a 1GB large pci mmio hole which is not enough and
creates conflicts when 352M vram is used.

This patch increases the pci mmio hole size on Lenovo x200 to allow
352M vram to work.

TEST: build and flash on target with 4GB ram or more, use nvramtool to
set gfx_uma_size to 352M and reboot.

Change-Id: I5ab066252339ac7d85149d91b09a9eaaaab3b5b6
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/16831
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/lenovo/t400/cmos.layout

@@ -139,6 +139,7 @@ enumerations
 11    9     96M
 11    10     160M
 11    11     224M
+11    12     352M
 12    0     Integrated Only
 12    1     Discrete Only
 

src/mainboard/lenovo/x200/cmos.layout

@@ -136,6 +136,7 @@ enumerations
 11    9     96M
 11    10    160M
 11    11    224M
+11    12    352M
 
 # -----------------------------------------------------------------
 checksums

src/mainboard/lenovo/x200/devicetree.cb

@@ -28,7 +28,7 @@ chip northbridge/intel/gm45
 		end
 	end
 
-	register "pci_mmio_size" = "1024"
+	register "pci_mmio_size" = "2048"
 
 	device domain 0 on
 		device pci 00.0 on

src/mainboard/roda/rk9/cmos.layout

@@ -124,6 +124,7 @@ enumerations
 11    9     96M
 11    10     160M
 11    11     224M
+11    12     352M
 # -----------------------------------------------------------------
 checksums
 

src/northbridge/intel/gm45/igd.c

@@ -157,7 +157,7 @@ void igd_compute_ggc(sysinfo_t *const sysinfo)
 			gfxsize = 4;
 		}
 		/* Handle invalid cmos settings */
-		if (gfxsize > 11)
+		if (gfxsize > 12)
 			gfxsize = 4;
 		sysinfo->ggc = 0x0300 | ((gfxsize + 1) << 4);
 		if (!(capid & (1 << (48 - 32))))