gma: Configure panel fitter / pipe scaler

If the framebuffer size is smaller than the display mode's resolution,
enable the panel fitter or pipe scaler (on Skylake+).

Change-Id: I0a648a7e7bf495a80636a589a74b698ecba7e7d5
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/17263
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: Nico Huber <nico.h@gmx.de>
diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template
index 7a83e77..7289dff 100644
--- a/common/hw-gfx-gma-config.ads.template
+++ b/common/hw-gfx-gma-config.ads.template
@@ -48,6 +48,7 @@
    Has_Pipeconf_BPC        : constant Boolean := CPU /= Haswell;
    Has_Plane_Control       : constant Boolean := CPU >= Skylake;
    Has_DSP_Linoff          : constant Boolean := CPU <= Ivybridge;
+   Has_PF_Pipe_Select      : constant Boolean := CPU in Ivybridge .. Haswell;
 
    ----- Panel power: -----
    Has_PP_Write_Protection : constant Boolean := CPU <= Ivybridge;