drm/mediatek: adjust dsi and mipi_tx probe sequence

mtk_mipi_tx is the phy of mtk_dsi.
mtk_dsi get the phy(mtk_mipi_tx) in probe().

So,  mtk_mipi_tx init should be ahead of mtk_dsi. Or mtk_dsi will
defer to wait mtk_mipi_tx probe done.
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_drv.c

@@ -669,8 +669,8 @@ static struct platform_driver * const mtk_drm_drivers[] = {
 	&mtk_disp_rdma_driver,
 	&mtk_dpi_driver,
 	&mtk_drm_platform_driver,
-	&mtk_dsi_driver,
 	&mtk_mipi_tx_driver,
+	&mtk_dsi_driver,
 };
 
 static int __init mtk_drm_init(void)