drm/vc4: Define missing PITCH0_SINK_PIX field

This is needed to support X/Y negative placement of planes using
T-format buffers.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180803092231.26446-2-boris.brezillon@bootlin.com

drivers/gpu/drm/vc4/vc4_regs.h

@@ -1037,6 +1037,10 @@ enum hvs_pixel_format {
 #define SCALER_TILE_HEIGHT_MASK			VC4_MASK(15, 0)
 #define SCALER_TILE_HEIGHT_SHIFT		0
 
+/* Common PITCH0 fields */
+#define SCALER_PITCH0_SINK_PIX_MASK		VC4_MASK(31, 26)
+#define SCALER_PITCH0_SINK_PIX_SHIFT		26
+
 /* PITCH0 fields for T-tiled. */
 #define SCALER_PITCH0_TILE_WIDTH_L_MASK		VC4_MASK(22, 16)
 #define SCALER_PITCH0_TILE_WIDTH_L_SHIFT	16