OMAP4 uses cross trigger interface(CTI) to route
performance monitor irq to GIC, so introduce cti
helpers to make access for cti easily.
Acked-by: NJean Pihet <j-pihet@ti.com>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>