asoc: wcd937x: clear interrupts using regmap irq framework

Add proper way to clear interrupts using regmap irq framework,
to avoid mismatch between interrupts handled and interrupts
cleared. wcd937x requires writing '1' and then '0' to clear
interrupt. Set a new regmap irq flag 'clear_ack' to indicate this.

Change-Id: I1346dc66735d3b5788e1cc0cfef772c9deacbfc1
Signed-off-by: Ramprasad Katkam <katkam@codeaurora.org>