ARM: pxa: pxa_cplds: honor probe deferral

The method to acquire the input interrupt was working in a platform data
based board, but was failing in a device-tree one when the gpio
controller was probed after pxa_cplds.

Use platform_get_irq() to benefit from the probe deferral
mechanism. Moreover, as seen in dm9000.c development, platform_get_irq()
doesn't honor the irq type IO resource (ie. edge rising for example),
and it must be passed again at irq request in a not device-tree build,
hence the irq_get_trigger_type() call.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>