gma panel: Introduce `Panel_Control` type

For now, `Panel_Control` only distinguishes `Panel_1` from `No_Panel`,
i.e. if a port has a panel attached or not. To ease future addition of
support for more than one panel, we already add loops and arrays around
it, though.

With the information, if a port has a panel attached, in `Port_Config`,
we can pass that on into Panel.* procedures and let those decide what
to do (e.g. do nothing if no panel is attached).

Change-Id: I83864bc86b48f65d9ba43e083b805ca09497cbb0
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/libgfxinit/+/38243
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/common/hw-gfx-gma-panel.ads b/common/hw-gfx-gma-panel.ads
index b968e29..baf47f7 100644
--- a/common/hw-gfx-gma-panel.ads
+++ b/common/hw-gfx-gma-panel.ads
@@ -40,22 +40,22 @@
 
    ----------------------------------------------------------------------------
 
-   procedure VDD_Override;
+   procedure VDD_Override (Panel : Panel_Control);
 
-   procedure On (Wait : Boolean := True);
+   procedure On (Panel : Panel_Control; Wait : Boolean := True);
 
-   procedure Wait_On;
+   procedure Wait_On (Panel : Panel_Control);
 
-   procedure Off;
+   procedure Off (Panel : Panel_Control);
 
    ----------------------------------------------------------------------------
 
-   procedure Backlight_On;
+   procedure Backlight_On (Panel : Panel_Control);
 
-   procedure Backlight_Off;
+   procedure Backlight_Off (Panel : Panel_Control);
 
-   procedure Set_Backlight (Level : Word16);
+   procedure Set_Backlight (Panel : Panel_Control; Level : Word16);
 
-   procedure Get_Max_Backlight (Level : out Word16);
+   procedure Get_Max_Backlight (Panel : Panel_Control; Level : out Word16);
 
 end HW.GFX.GMA.Panel;