[ARM] pxa: expand irq support for PXA93x and PXA950

PXA93x/950 has additional 64 GPIOs, each is a secondary interrupt
source for IRQ_GPIO_2_x, extend PXA_GPIO_IRQ_{BASE,NUM}.

PXA93x/950 specific IRQ definitions are added as well.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>