drm/dsi: Add mipi_dsi_set_maximum_return_packet_size() helper

This function can be used to set the maximum return packet size for a
MIPI DSI peripheral.

Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
[treding: endianess, kerneldoc, return value]
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 4eeb4a5..4a4e9d7 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -153,6 +153,8 @@
 
 int mipi_dsi_attach(struct mipi_dsi_device *dsi);
 int mipi_dsi_detach(struct mipi_dsi_device *dsi);
+int mipi_dsi_set_maximum_return_packet_size(struct mipi_dsi_device *dsi,
+					    u16 value);
 ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
 				  const void *data, size_t len);
 ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,