[ARM] pxa: cleanup the coding style of pxa_gpio_set_type()

by

1. wrapping long lines and making comments tidy

2. using IRQ_TYPE_* instead of migration macros __IRQT_*

3. introduce a pr_debug() for the commented printk(KERN_DEBUG ...)
   stuff

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