gma-display_probing: Only check display type on DVI-I

On DVI-I connectors the DDC is shared between the analog and digital
parts. To decide which path to take we checked the digital input bit
of the EDID. We did this overeagerly for all ports, which broke com-
patibility with DP adapters (the DP realm is very complex and we are
supposed to discover the whole downstream hierarchie, which obviously
would be overkill).

Change-Id: Ifc53e8ab985695e6e4ff1d42659826710a50eae9
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/20135
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template
index b4e52f6..e82b133 100644
--- a/common/hw-gfx-gma-config.ads.template
+++ b/common/hw-gfx-gma-config.ads.template
@@ -39,6 +39,7 @@
 
    Has_Internal_Display    : constant Boolean := Internal_Display /= None;
    Internal_Is_EDP         : constant Boolean := Internal_Display = DP;
+   Have_DVI_I              : constant Boolean := Analog_I2C_Port /= PCH_DAC;
    Has_Presence_Straps     : constant Boolean := CPU /= Broxton;
 
    ----- CPU pipe: --------