drivers/intel/gma/acpi: Provide default definition for displays

Use it wherever the standard numbers were copied to. Bit 31 is set
at runtime unconditionally, so we don't need it here.

Change-Id: I0d853c3b8250a2c7b2d1a91985a555e4b17ad76c
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39731
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/lenovo/t420s/devicetree.cb b/src/mainboard/lenovo/t420s/devicetree.cb
index 5cf3165..2fde40f 100644
--- a/src/mainboard/lenovo/t420s/devicetree.cb
+++ b/src/mainboard/lenovo/t420s/devicetree.cb
@@ -1,6 +1,5 @@
 chip northbridge/intel/sandybridge
-	register "gfx.ndid" = "3"
-	register "gfx.did" = "{ 0x80000100, 0x80000240, 0x80000410, 0x80000410, 0x00000005 }"
+	register "gfx" = "GMA_STATIC_DISPLAYS(1)"
 
 	# Enable DisplayPort Hotplug with 6ms pulse
 	register "gpu_dp_d_hotplug" = "0x06"
@@ -12,7 +11,6 @@
 	register "gpu_panel_power_down_delay" = "300"		# T5+T6: 30ms
 	register "gpu_panel_power_backlight_on_delay" = "2000"	# T3: 200ms
 	register "gpu_panel_power_backlight_off_delay" = "2000"	# T4: 200ms
-	register "gfx.use_spread_spectrum_clock" = "1"
 	register "gpu_cpu_backlight" = "0x1155"
 	register "gpu_pch_backlight" = "0x06100610"