clk: rockchip: add rk3228 sclk_sdio_src ID

This patch exports sdio src clock for dts reference.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
diff --git a/include/dt-bindings/clock/rk3228-cru.h b/include/dt-bindings/clock/rk3228-cru.h
index 56f841c..55655ab 100644
--- a/include/dt-bindings/clock/rk3228-cru.h
+++ b/include/dt-bindings/clock/rk3228-cru.h
@@ -49,6 +49,7 @@
 #define SCLK_EMMC_DRV		117
 #define SCLK_SDMMC_SAMPLE	118
 #define SCLK_SDIO_SAMPLE	119
+#define SCLK_SDIO_SRC		120
 #define SCLK_EMMC_SAMPLE	121
 #define SCLK_VOP		122
 #define SCLK_HDMI_HDCP		123