mb/asrock/b85m_pro4: Enable VGA port

Now that libgfxinit has been fixed, trying to enable the Analog port no
longer hangs the system, nor fills the monitor with unreadable garbage.

Tested with linear framebuffer, displays correctly on a 1920x1080 VGA
monitor. Scaling also works when a smaller HDMI monitor is connected as
well. Legacy VGA text mode is also functional on either monitor, too.

Change-Id: Ie2f88edcb7ed1984adebf2af23195767af13654c
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43560
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/asrock/b85m_pro4/gma-mainboard.ads

@@ -11,8 +11,7 @@ private package GMA.Mainboard is
    ports : constant Port_List :=
      (HDMI1,  -- DVI-D
       HDMI3,  -- HDMI
-      -- FIXME: Haswell VGA support in libgfxinit is broken
-      -- Analog, -- VGA
+      Analog, -- VGA
       others => Disabled);
 
 end GMA.Mainboard;