PRM_IO_PMCTRL_OFFSET need not be same for all SOCs hence
remove hardcoding and use the value provided by the omap_prcm_irq_setup
structure. This is done to support IO wakeup on am437x series.
Signed-off-by: Keerthy <j-keerthy@ti.com> Reviewed-by: Paul Walmsley <paul@pwsan.com> Signed-off-by: Paul Walmsley <paul@pwsan.com>