gma bxt panel: Correct panel backlight handling

Change-Id: Icfad261fb4d5ff478974948c0148880c5b8cb40c
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/libgfxinit/+/38265
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template
index 01a67c1..39fa825 100644
--- a/common/hw-gfx-gma-config.ads.template
+++ b/common/hw-gfx-gma-config.ads.template
@@ -182,6 +182,7 @@
    Use_PP_VDD_Override           : <genbool> := Up_To_Ironlake;
    Has_PCH_Panel_Power           : <genbool> := Ironlake_On;
    Has_PP_Divisor_Reg            : <genbool> := not Gen_Broxton;
+   Has_New_Backlight_Control     : <genbool> := Gen_Broxton;
 
    ----------- PCH/FDI: ---------
    Has_PCH                       : <genbool> := not Gen_Broxton and not Gen_G45;