MA-19979[Android] Add DRM_FORMAT_ARGB8888 support for imx8ulp as recovery mode required

Even driver don't support alpha in imx8ulp, still add DRM_FORMAT_ARGB8888 format
for primary plane. Because android recovery mode only support DRM_FORMAT_RGBA8888,
DRM_FORMAT_ARGB8888, DRM_FORMAT_XBGR8888, DRM_FORMAT_BGRA8888.
So declare DRM_FORMAT_ARGB8888 is supported in driver and discard the alpha when
set format for framebuffer.

Change-Id: I81e1d36565f61ee5425d34fb672a531ecebd9155
Signed-off-by: Zhang Bo <bo.zhang@nxp.com>

drivers/gpu/drm/imx/dcnano/dcnano-crtc.c

@@ -273,6 +273,10 @@ static void dcnano_crtc_atomic_enable(struct drm_crtc *crtc,
 		case DRM_FORMAT_XRGB8888:
 			primary_fb_fmt = FBCFG_FORMAT_R8G8B8;
 			break;
+		case DRM_FORMAT_ARGB8888:
+			/* discard alpha, only used in android recovery mode */
+			primary_fb_fmt = FBCFG_FORMAT_R8G8B8;
+			break;
 		}
 	}
 

drivers/gpu/drm/imx/dcnano/dcnano-plane.c

@@ -28,6 +28,7 @@
 static const u32 dcnano_primary_plane_formats[] = {
 	DRM_FORMAT_RGB565,
 	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ARGB8888, /* only used in android recovery mode */
 };
 
 static unsigned int