drm: bridge: it66121: Fix the register page length

Set the register page length or window length to
0x100 according to the documentation.

Fixes: 988156dc ("drm: bridge: add it66121 driver")
Signed-off-by: NNicolas Belin <nbelin@baylibre.com>
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220316135733.173950-3-nbelin@baylibre.com

drivers/gpu/drm/bridge/ite-it66121.c

@@ -227,7 +227,7 @@ static const struct regmap_range_cfg it66121_regmap_banks[] = {
 		.selector_mask = 0x1,
 		.selector_shift = 0,
 		.window_start = 0x00,
-		.window_len = 0x130,
+		.window_len = 0x100,
 	},
 };