soc/intel/common/block: Add Intel VGA early graphics support

This patch introduces an early graphics driver which can be used in
romstage in cache-as-ram mode. The implementation relies on
`libgfxinit' and provide VGA text mode support.

SoCs wanting to take advantage of this driver must implement the
`early_graphics_soc_panel_init' function to set the panel power
sequence timing parameters.

BUG=b:252792591
BRANCH=firmware-brya-14505.B
TEST=Graphics bring up observed on skolas with extra patches

Change-Id: Ie4ad1215e5fadd0adc1271b6bd6ddb0ea258cb5b
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70299
Reviewed-by: Tarun Tuli <taruntuli@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Maulik Vaghela <maulikvaghela@google.com>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/intel/gma/gma-gfx_init.ads

@@ -11,6 +11,9 @@ is
    procedure gfxinit (lightup_ok : out Interfaces.C.int);
    pragma Export (C, gfxinit, "gma_gfxinit");
 
+   procedure gfxstop (stop_ok : out Interfaces.C.int);
+   pragma Export (C, gfxstop, "gma_gfxstop");
+
    ----------------------------------------------------------------------------
 
    function c_fb_add_framebuffer_info

src/drivers/intel/gma/hires_fb/gma-gfx_init.adb

@@ -97,4 +97,17 @@ is
       end if;
    end gfxinit;
 
+   procedure gfxstop (stop_ok : out Interfaces.C.int)
+   is
+      success : boolean;
+   begin
+      HW.GFX.GMA.Initialize (Clean_State => True,
+      			     Success => success);
+      if success then
+         stop_ok := 1;
+      else
+         stop_ok := 0;
+      end if;
+   end gfxstop;
+
 end GMA.GFX_Init;

src/drivers/intel/gma/libgfxinit.h

@@ -17,6 +17,7 @@ enum {
 };
 
 void gma_gfxinit(int *lightup_ok);
+void gma_gfxstop(int *stop_ok);
 int gma_read_edid(unsigned char edid[], int port);
 
 #endif

src/drivers/intel/gma/text_fb/gma-gfx_init.adb

@@ -56,4 +56,17 @@ is
       end if;
    end gfxinit;
 
+   procedure gfxstop (stop_ok : out Interfaces.C.int)
+   is
+      success : boolean;
+   begin
+      HW.GFX.GMA.Initialize (Clean_State => True,
+      			     Success => success);
+      if success then
+         stop_ok := 1;
+      else
+         stop_ok := 0;
+      end if;
+   end gfxstop;
+
 end GMA.GFX_Init;