[ARM] 4440/1: PXA: enable the checking of ICIP2 for IRQs

ICIP2 is not examined during IRQ entrance, this patch add the
checking if the processor is PXA27x or later, with CoreG bits
in CPUID (Core Generation) > 1

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>