nb/intel/{gm45,i945,pineview}: Use macro instead of GGC address

Change-Id: I233e835180fd445961b6deb74ea7afc2821c236e
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/28909
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/northbridge/intel/pineview/gma.c

@@ -98,7 +98,7 @@ static void intel_gma_init(const struct northbridge_intel_pineview_config *info,
 
 	gtt_setup(mmio);
 
-	pci_write_config16(vga, 0x52, 0x130);
+	pci_write_config16(vga, GGC, 0x130);
 
 	/* Disable VGA.  */
 	write32(mmio + VGACNTRL, VGA_DISP_DISABLE);