feat(ti): add gic save and restore calls

Add functions to save and restore GICv3 redist and dist contexts during
low power mode and then call these during the suspend entry and finish
psci handlers.

Change-Id: I26c2c0f3b7fc925de3b349499fa42d2405441577
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
diff --git a/plat/ti/k3/include/k3_gicv3.h b/plat/ti/k3/include/k3_gicv3.h
index 2329a16..2c68a75 100644
--- a/plat/ti/k3/include/k3_gicv3.h
+++ b/plat/ti/k3/include/k3_gicv3.h
@@ -14,5 +14,7 @@
 void k3_gic_cpuif_enable(void);
 void k3_gic_cpuif_disable(void);
 void k3_gic_pcpu_init(void);
+void k3_gic_save_context(void);
+void k3_gic_restore_context(void);
 
 #endif /* K3_GICV3_H */