drm: meson: venc: set the correct macrovision max amplitude value

According to the register description of ENCI_MACV_MAX_AMP, the
macrovision max amplitude value should be:
- hdmi 480i => 0xb
- hdmi 576i => 0x7

The max value is 0x7ff (10 bits).
Signed-off-by: Julien Masson <jmasson@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/86mui782dt.fsf@baylibre.com

drivers/gpu/drm/meson/meson_venc.c

@@ -192,7 +192,7 @@ union meson_hdmi_venc_mode meson_hdmi_enci_mode_480i = {
 		.hso_end = 129,
 		.vso_even = 3,
 		.vso_odd = 260,
-		.macv_max_amp = 0x810b,
+		.macv_max_amp = 0xb,
 		.video_prog_mode = 0xf0,
 		.video_mode = 0x8,
 		.sch_adjust = 0x20,
@@ -212,7 +212,7 @@ union meson_hdmi_venc_mode meson_hdmi_enci_mode_576i = {
 		.hso_end = 129,
 		.vso_even = 3,
 		.vso_odd = 260,
-		.macv_max_amp = 8107,
+		.macv_max_amp = 0x7,
 		.video_prog_mode = 0xff,
 		.video_mode = 0x13,
 		.sch_adjust = 0x28,