gma power: Allow to explicitly enable DDI/Aux power

We used to enable power for DP-aux channels quite implicitly by faking
configs that use a specific port.  As Tiger Lake requires us to enable
a DDI port's power late during the modesetting sequence,  we introduce
a new API for such cases, and also use it for the DP-aux case.

Tested on HSW, and BXT & CFL where we enable PW2 explicitly now.

Change-Id: I1fd6348ff4855557166495613c6a181f85a818f4
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.sourcearcade.org/c/libgfxinit/+/461
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/common/hw-gfx-gma.adb b/common/hw-gfx-gma.adb
index 39a6426..e26e751 100644
--- a/common/hw-gfx-gma.adb
+++ b/common/hw-gfx-gma.adb
@@ -155,6 +155,10 @@
         (Port_Cfg, Pipe, Pipe_Cfg.Port, Pipe_Cfg.Mode, Success);
 
       if Success then
+         Power_And_Clocks.Power_Up (Pipe_Cfg.Port, Success);
+      end if;
+
+      if Success then
          Connector_Info.Preferred_Link_Setting (Port_Cfg, Success);
       end if;