ti: k3: common: Add basic PSCI reset support

Use TI-SCI messages to request reset from system controller firmware.

Signed-off-by: Andrew F. Davis <afd@ti.com>
diff --git a/plat/ti/k3/common/k3_psci.c b/plat/ti/k3/common/k3_psci.c
index 20d1ae6..4c501f5 100644
--- a/plat/ti/k3/common/k3_psci.c
+++ b/plat/ti/k3/common/k3_psci.c
@@ -92,8 +92,8 @@
 
 static void __dead2 k3_system_reset(void)
 {
-	/* TODO: Indicate to System firmware about system reset */
-	STUB();
+	/* Send the system reset request to system firmware */
+	ti_sci_core_reboot();
 
 	while (true)
 		wfi();