clk: rockchip: add general gpu soft-reset on rk3399

Add the id for the general gpu soft-reset, that got documented only in
newer TRM versions.

Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

include/dt-bindings/clock/rk3399-cru.h

@@ -671,6 +671,7 @@
 #define SRST_P_EDP_CTRL			285
 
 /* cru_softrst_con18 */
+#define SRST_A_GPU			288
 #define SRST_A_GPU_NOC			289
 #define SRST_A_GPU_GRF			290
 #define SRST_PVTM_GPU			291