zynqmp: pm: Add IOCTLs for global storage access

Add IOCTLs to read/write global general storage and
persistent global general storage registers access.

Signed-off-by: Rajan Vaja <rajanv@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>
diff --git a/plat/xilinx/zynqmp/pm_service/pm_api_ioctl.h b/plat/xilinx/zynqmp/pm_service/pm_api_ioctl.h
index b290574..548ac9e 100644
--- a/plat/xilinx/zynqmp/pm_service/pm_api_ioctl.h
+++ b/plat/xilinx/zynqmp/pm_service/pm_api_ioctl.h
@@ -27,6 +27,10 @@
 	IOCTL_GET_PLL_FRAC_MODE,
 	IOCTL_SET_PLL_FRAC_DATA,
 	IOCTL_GET_PLL_FRAC_DATA,
+	IOCTL_WRITE_GGS,
+	IOCTL_READ_GGS,
+	IOCTL_WRITE_PGGS,
+	IOCTL_READ_PGGS,
 };
 
 enum rpu_oper_mode {