soc: swr-mstr: Add logic to recursively trigger slave irq handler

Soundwire slave interrupt is only edge type, so any pending slave
side interrupts could not cause a new slave interrupt, if
they are triggered before clearing of existing interrupts.
Recursively trigger slave irq until there are no pending slave
interrupts to handle this issue.

Change-Id: I254f2467f09172490796114b48f1f0feb604ad17
Signed-off-by: Ramprasad Katkam <katkam@codeaurora.org>