drm/vc4: vec: Fix definition of PAL-M mode

PAL-M is a Brazilian analog TV standard that uses a PAL-style chroma
subcarrier at 3.575611[888111] MHz on top of 525-line (480i60) timings.
This commit makes the driver actually use the proper VEC preset for this
mode instead of just changing PAL subcarrier frequency.
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Link: https://lore.kernel.org/r/20220728-rpi-analog-tv-properties-v4-25-60d38873f782@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_vec.c

@@ -69,6 +69,7 @@
 #define VEC_CONFIG0_STD_MASK		GENMASK(1, 0)
 #define VEC_CONFIG0_NTSC_STD		0
 #define VEC_CONFIG0_PAL_BDGHI_STD	1
+#define VEC_CONFIG0_PAL_M_STD		2
 #define VEC_CONFIG0_PAL_N_STD		3
 
 #define VEC_SCHPH			0x108
@@ -255,10 +256,9 @@ static const struct vc4_vec_tv_mode vc4_vec_tv_modes[] = {
 		.config1 = VEC_CONFIG1_C_CVBS_CVBS,
 	},
 	[VC4_VEC_TV_MODE_PAL_M] = {
-		.mode = &pal_mode,
-		.config0 = VEC_CONFIG0_PAL_BDGHI_STD,
-		.config1 = VEC_CONFIG1_C_CVBS_CVBS | VEC_CONFIG1_CUSTOM_FREQ,
-		.custom_freq = 0x223b61d1,
+		.mode = &ntsc_mode,
+		.config0 = VEC_CONFIG0_PAL_M_STD,
+		.config1 = VEC_CONFIG1_C_CVBS_CVBS,
 	},
 };