drm/rockchip/dsi: correct the grf_switch_reg name

For the RK3399, the grf_switch_reg name should be RK3399_GRF_SOC_CON20,
not RK3399_GRF_SOC_CON19.
Signed-off-by: NChris Zhong <zyw@rock-chips.com>
Reviewed-by: NBrian Norris <briannorris@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1490147691-4489-5-git-send-email-zyw@rock-chips.com

drivers/gpu/drm/rockchip/dw-mipi-dsi.c

@@ -34,7 +34,7 @@
 #define RK3288_DSI0_SEL_VOP_LIT		BIT(6)
 #define RK3288_DSI1_SEL_VOP_LIT		BIT(9)
 
-#define RK3399_GRF_SOC_CON19		0x6250
+#define RK3399_GRF_SOC_CON20		0x6250
 #define RK3399_DSI0_SEL_VOP_LIT		BIT(0)
 #define RK3399_DSI1_SEL_VOP_LIT		BIT(4)
 
@@ -1151,7 +1151,7 @@ static struct dw_mipi_dsi_plat_data rk3288_mipi_dsi_drv_data = {
 static struct dw_mipi_dsi_plat_data rk3399_mipi_dsi_drv_data = {
 	.dsi0_en_bit = RK3399_DSI0_SEL_VOP_LIT,
 	.dsi1_en_bit = RK3399_DSI1_SEL_VOP_LIT,
-	.grf_switch_reg = RK3399_GRF_SOC_CON19,
+	.grf_switch_reg = RK3399_GRF_SOC_CON20,
 	.grf_dsi0_mode = RK3399_GRF_DSI_MODE,
 	.grf_dsi0_mode_reg = RK3399_GRF_SOC_CON22,
 	.flags = DW_MIPI_NEEDS_PHY_CFG_CLK | DW_MIPI_NEEDS_GRF_CLK,