With sparse IRQs the driver shouldn't depend at all on
any IRQ values coming from board-file.

Remove every occurences of pdata->irq_base/end.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NBenoit Cousson <b-cousson@ti.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>