mb/purism/librem_cnl: Enable HDMI1 output for Mini native graphics init

Enable HDMI1 output, which corresponds to the physical DisplayPort
connector, so passive adapters to DVI or HDMI will work with native
graphics init.

Change-Id: I95a147978697f4af092fe61ceacd2e725155d489
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77671
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/mainboard/purism/librem_cnl/variants/librem_mini/gma-mainboard.ads

@@ -10,6 +10,7 @@ private package GMA.Mainboard is
 
    ports : constant Port_List :=
      (DP1,  -- DisplayPort connector
+      HDMI1, -- DisplayPort connector, needed for passive DisplayPort to DVI/HDMI adapters
       DP2,  -- HDMI connector through Parade DP175 LSPCON
       others => Disabled);