feat(ti): add PSCI system_off support

Send a TI-SCI control message to system firmware to power down the board.

Signed-off-by: Andrew Davis <afd@ti.com>
Change-Id: I6b8fa64baa94da078db82fc8e115630c9f200b3d
diff --git a/plat/ti/k3/common/k3_bl31_setup.c b/plat/ti/k3/common/k3_bl31_setup.c
index 457c95d..6436e7a 100644
--- a/plat/ti/k3/common/k3_bl31_setup.c
+++ b/plat/ti/k3/common/k3_bl31_setup.c
@@ -120,6 +120,10 @@
 	k3_gic_init();
 
 	ti_sci_init();
+
+	if (ti_sci_device_get(PLAT_BOARD_DEVICE_ID)) {
+		WARN("Unable to take system power reference\n");
+	}
 }
 
 void platform_mem_init(void)