pcmcia: pxa: replace IRQ_GPIO() with gpio_to_irq()

Since commit 6384fd "ARM: pxa: rename IRQ_GPIO to PXA_GPIO_TO_IRQ",
I got buid errors due to implicit declaration of function 'IRQ_GPIO'.

Use common gpio_to_irq() to replace machine dependant macro IRQ_GPIO().

Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Ian Molton <spyro@f2s.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Zhuang <haojian.zhuang@marvell.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>