GICv3: Introduce power management APIs for Redistributor

Some GICv3 implementations have provision for power management
operations at Redistributor level. This patch introduces and provides
place-holders for Redistributor power management. The default
implementations are empty stubs, but are weakly bound so as to enable
implementation-specific drivers to override them.

Change-Id: I4fec1358693d3603ca5dce242a2f7f0e730516d8
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/drivers/arm/gicv3.h b/include/drivers/arm/gicv3.h
index b7ad778..0f6034c 100644
--- a/include/drivers/arm/gicv3.h
+++ b/include/drivers/arm/gicv3.h
@@ -259,6 +259,8 @@
 void gicv3_driver_init(const gicv3_driver_data_t *plat_driver_data);
 void gicv3_distif_init(void);
 void gicv3_rdistif_init(unsigned int proc_num);
+void gicv3_rdistif_on(unsigned int proc_num);
+void gicv3_rdistif_off(unsigned int proc_num);
 void gicv3_cpuif_enable(unsigned int proc_num);
 void gicv3_cpuif_disable(unsigned int proc_num);
 unsigned int gicv3_get_pending_interrupt_type(void);