x86: Add initial video device init for Intel GMA

Intel's Graphics Media Accelerator (GMA) is a generic name for a wide range
of video devices. Add code to set up the hardware on ivybridge. Part of the
init happens in native code, part of it happens in a 16-bit option ROM for
those nostalgic for the 1970s.

Signed-off-by: Simon Glass <sjg@chromium.org>

lib/fdtdec.c

@@ -77,6 +77,7 @@ static const char * const compat_names[COMPAT_COUNT] = {
 	COMPAT(MEMORY_SPD, "memory-spd"),
 	COMPAT(INTEL_PANTHERPOINT_AHCI, "intel,pantherpoint-ahci"),
 	COMPAT(INTEL_MODEL_206AX, "intel,model-206ax"),
+	COMPAT(INTEL_GMA, "intel,gma"),
 };
 
 const char *fdtdec_get_compatible(enum fdt_compat_id id)