Input: ti_am335x_tsc - fix HWPEN interrupt handling

Remove write to REG_IRQCLR and REG_IRQWAKEUP in interrupt handler for
IRQENB_HW_PEN as the resume handler should and does clear REG_IRQWAKEUP.
IRQENB_HW_PEN bit is set in irqclr so that all interrupts get cleared
later so let IRQENB_HW_PEN be cleared by that.

Without this patch wakeup events from TSC_ADC do not work because pending
interrupts in TSC_ADC were causing HW_PEN interrupt, needed for wake from
suspend modes, to get disabled immediately by IRQ handler after being
enabled and preventing wake from happening.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>