drm/mediatek: dpi: Only enable dpi after the bridge is enabled

Enabling the dpi too early causes glitches on screen.

Move the call to mtk_dpi_enable() at the end of the bridge_enable
callback to ensure everything is setup properly before enabling dpi.

Fixes: 9e629c17 ("drm/mediatek: Add DPI sub driver")
Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20220701035845.16458-16-rex-bc.chen@mediatek.com/Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_dpi.c

@@ -426,7 +426,6 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
 	if (dpi->pinctrl && dpi->pins_dpi)
 		pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
 
-	mtk_dpi_enable(dpi);
 	return 0;
 
 err_pixel:
@@ -648,6 +647,7 @@ static void mtk_dpi_bridge_enable(struct drm_bridge *bridge)
 
 	mtk_dpi_power_on(dpi);
 	mtk_dpi_set_display_mode(dpi, &dpi->mode);
+	mtk_dpi_enable(dpi);
 }
 
 static enum drm_mode_status