vo_gpu: mark --gamma-factor and --gamma-auto with deprecation warnings

This was forgotten in commit 2207236.

Author: sfan5

video/out/gpu/video.c

@@ -366,8 +366,10 @@ const struct m_sub_options gl_video_conf = {
     .opts = (const m_option_t[]) {
         {"gpu-dumb-mode", OPT_CHOICE(dumb_mode,
             {"auto", 0}, {"yes", 1}, {"no", -1})},
-        {"gamma-factor", OPT_FLOAT(gamma), M_RANGE(0.1, 2.0)},
-        {"gamma-auto", OPT_FLAG(gamma_auto)},
+        {"gamma-factor", OPT_FLOAT(gamma), M_RANGE(0.1, 2.0),
+            .deprecation_message = "no replacement"},
+        {"gamma-auto", OPT_FLAG(gamma_auto),
+            .deprecation_message = "no replacement"},
         {"target-prim", OPT_CHOICE_C(target_prim, mp_csp_prim_names)},
         {"target-trc", OPT_CHOICE_C(target_trc, mp_csp_trc_names)},
         {"target-peak", OPT_CHOICE(target_peak, {"auto", 0}),