mfd: wcd934x: Add macro for adding new interrupts

mfd: wcd934x: Add macro for adding new interrupts

Currently only two interrupts supported is added in wcd934x interrupt controller,
however if we are adding more interrupts the file will become too much unreadable.

So add a macro to make adding new interrupts easy and also convert existing
slim and soundwire interrupts to use it.
This is in preparation to enable Multi Button Headset Control support on this
codec.

WCD934x supports Multi Button Headset control which enable headset detection
along with headset button detection.

This patch adds interrupts required for MBHC functionality.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>