ARM: OMAP4+: PRM: remove "wkup" event

"wkup" event at bit offset 0 exists only on OMAP3.
OMAP4430/60 PRM_IRQSTATUS_A9, OMAP5/DRA7 PRM_IRQSTATUS_MPU

register bit 0 is DPLL_CORE_RECAL_ST not wakeup event like OMAP3.

The same applies to AM437x as well.

Remove the wrong definition.

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>