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 <[e-mail]>
Signed-off-by: Ville Syrjälä <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Reviewed-by: Sam Ravnborg <[e-mail]>
Acked-by: Daniel Vetter <[e-mail]>

drivers/gpu/drm/drm_color_mgmt.c

···
  *
  * 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

···
 	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