gma hsw bdw: Add DDI buffer translations

Change-Id: Ib87be86e2853e6b9df7e19dd9cb80d4f7effefc5
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/20166
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/common/hw-gfx-gma-config.ads.template b/common/hw-gfx-gma-config.ads.template
index f9fe429..6839b91 100644
--- a/common/hw-gfx-gma-config.ads.template
+++ b/common/hw-gfx-gma-config.ads.template
@@ -92,7 +92,7 @@
                                                   and CPU_Var = Normal)
                                                  or CPU >= Skylake;
 
-   Has_DDI_Buffer_Trans    : constant Boolean := False;
+   Has_DDI_Buffer_Trans    : constant Boolean := CPU in Haswell .. Broadwell;
    Has_Low_Voltage_Swing   : constant Boolean := CPU >= Broxton;
 
    Need_DP_Aux_Mutex       : constant Boolean := False; -- Skylake & (PSR | GTC)
@@ -211,6 +211,8 @@
 
    Default_DDI_HDMI_Buffer_Translation : constant DDI_HDMI_Buf_Trans_Range :=
      (case CPU is
+         when Haswell   => 6,
+         when Broadwell => 7,
          when Broxton   => 8,
          when others    => 0);