drm: Constify drm_color_lut_check()

drm_color_lut_check() doens't modify the passed in blob so
let's make it const.

Also s/uint32_t/u32/ while at it.

v2: Reduce line wraps (Sam)

Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129170609.5718-1-ville.syrjala@linux.intel.comReviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_color_mgmt.c

@@ -474,10 +474,9 @@ EXPORT_SYMBOL(drm_plane_create_color_properties);
  *
  * Returns 0 on success, -EINVAL on failure.
  */
-int drm_color_lut_check(struct drm_property_blob *lut,
-			uint32_t tests)
+int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests)
 {
-	struct drm_color_lut *entry;
+	const struct drm_color_lut *entry;
 	int i;
 
 	if (!lut || !tests)

include/drm/drm_color_mgmt.h

@@ -96,6 +96,5 @@ enum drm_color_lut_tests {
 	DRM_COLOR_LUT_NON_DECREASING = BIT(1),
 };
 
-int drm_color_lut_check(struct drm_property_blob *lut,
-			uint32_t tests);
+int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests);
 #endif