ASoC: wcd: update flags passed while registering codec IRQ handler

Add IRQF_ONESHOT flag while requesting for irq, if we request
only threaded handler without normal handler this flag is needed.

Change-Id: I78f2cc018ea339e75ab78792d5c4193759f42134
Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>