imx: imx8qx: add system reset support

Add system reset support for i.MX8QX,
when Linux kernel issues "reboot" command,
TF-A will send command to inform system
controller to reset whole board according
to board design, tested on i.MX8QX MEK board.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
diff --git a/plat/imx/common/imx8_psci.c b/plat/imx/common/imx8_psci.c
index 0b0dcb5..37eda3e 100644
--- a/plat/imx/common/imx8_psci.c
+++ b/plat/imx/common/imx8_psci.c
@@ -19,4 +19,11 @@
 	panic();
 }
 
+void __dead2 imx_system_reset(void)
+{
+	sc_pm_reset(ipc_handle, SC_PM_RESET_TYPE_BOARD);
+	wfi();
+	ERROR("system reset failed.\n");
+	panic();
+}
 
diff --git a/plat/imx/common/include/plat_imx8.h b/plat/imx/common/include/plat_imx8.h
index 640d60e..3b5f4ec 100644
--- a/plat/imx/common/include/plat_imx8.h
+++ b/plat/imx/common/include/plat_imx8.h
@@ -18,4 +18,5 @@
 void plat_gic_pcpu_init(void);
 
 void __dead2 imx_system_off(void);
+void __dead2 imx_system_reset(void);
 #endif /*__PLAT_IMX8_H__ */