drm/i915: Print pretty names for pixel formats

Use drm_get_format_name to print more readable pixel format names
in debug output.

Also unify the debug messages to say "unsupported pixel format",
which better describes what is going on.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/i915/intel_display.c

@@ -8945,7 +8945,8 @@ int intel_framebuffer_init(struct drm_device *dev,
 	case DRM_FORMAT_XRGB1555:
 	case DRM_FORMAT_ARGB1555:
 		if (INTEL_INFO(dev)->gen > 3) {
-			DRM_DEBUG("invalid format: 0x%08x\n", mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n",
+				  drm_get_format_name(mode_cmd->pixel_format));
 			return -EINVAL;
 		}
 		break;
@@ -8956,7 +8957,8 @@ int intel_framebuffer_init(struct drm_device *dev,
 	case DRM_FORMAT_XBGR2101010:
 	case DRM_FORMAT_ABGR2101010:
 		if (INTEL_INFO(dev)->gen < 4) {
-			DRM_DEBUG("invalid format: 0x%08x\n", mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n",
+				  drm_get_format_name(mode_cmd->pixel_format));
 			return -EINVAL;
 		}
 		break;
@@ -8965,12 +8967,14 @@ int intel_framebuffer_init(struct drm_device *dev,
 	case DRM_FORMAT_YVYU:
 	case DRM_FORMAT_VYUY:
 		if (INTEL_INFO(dev)->gen < 5) {
-			DRM_DEBUG("invalid format: 0x%08x\n", mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n",
+				  drm_get_format_name(mode_cmd->pixel_format));
 			return -EINVAL;
 		}
 		break;
 	default:
-		DRM_DEBUG("unsupported pixel format 0x%08x\n", mode_cmd->pixel_format);
+		DRM_DEBUG("unsupported pixel format: %s\n",
+			  drm_get_format_name(mode_cmd->pixel_format));
 		return -EINVAL;
 	}