drm: renesas: shmobile: Fix ARGB32 overlay format typo

When configuring a CHn Source Image Format Register (LDBBSIFR), one
should use the corresponding LDBBSIFR_RPKF_* definition for overlay
planes, not the DDFR_PKF_* definition for the primary plane.

Fortunately both definitions resolve to the same value, so this bug did
not cause any harm.
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/34f8d51539c048e264699ca869ad9d7a952cd69f.1694767209.git.geert+renesas@glider.be

drivers/gpu/drm/renesas/shmobile/shmob_drm_plane.c

@@ -94,10 +94,10 @@ static void __shmob_drm_plane_setup(struct shmob_drm_plane *splane,
 		format |= LDBBSIFR_AL_1 | LDBBSIFR_RY | LDBBSIFR_RPKF_RGB24;
 		break;
 	case DRM_FORMAT_ARGB8888:
-		format |= LDBBSIFR_AL_PK | LDBBSIFR_RY | LDDFR_PKF_ARGB32;
+		format |= LDBBSIFR_AL_PK | LDBBSIFR_RY | LDBBSIFR_RPKF_ARGB32;
 		break;
 	case DRM_FORMAT_XRGB8888:
-		format |= LDBBSIFR_AL_1 | LDBBSIFR_RY | LDDFR_PKF_ARGB32;
+		format |= LDBBSIFR_AL_1 | LDBBSIFR_RY | LDBBSIFR_RPKF_ARGB32;
 		break;
 	case DRM_FORMAT_NV12:
 	case DRM_FORMAT_NV21: