gpu: ipu-v3: Add ipu_stride_to_bytes()

Adds ipu_stride_to_bytes(), which converts a pixel stride to bytes,
suitable for passing to cpmem.

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/include/video/imx-ipu-v3.h b/include/video/imx-ipu-v3.h
index ae44eb0..f24ef9a 100644
--- a/include/video/imx-ipu-v3.h
+++ b/include/video/imx-ipu-v3.h
@@ -333,6 +333,7 @@
 enum ipu_color_space ipu_drm_fourcc_to_colorspace(u32 drm_fourcc);
 enum ipu_color_space ipu_pixelformat_to_colorspace(u32 pixelformat);
 enum ipu_color_space ipu_mbus_code_to_colorspace(u32 mbus_code);
+int ipu_stride_to_bytes(u32 pixel_stride, u32 pixelformat);
 bool ipu_pixelformat_is_planar(u32 pixelformat);
 int ipu_degrees_to_rot_mode(enum ipu_rotate_mode *mode, int degrees,
 			    bool hflip, bool vflip);