soc: swr-mstr: Fix random headset detection issue on scuba

When headset is inserted and reboot device sometimes
headset is not detected after reboot as host_irq from
swr slave gets masked. This is because of cmd error seen
after clearing all irq which results in fifo flush.
Read swrslave irq before clearing so as to resolve cmd error.
Also enable slave irq only after clearing enum interrupt at
master which results in proper enabling of irq.

Change-Id: Id66029c65c4d813391bfeb8c0c619560f298eeab
Signed-off-by: Vatsal Bucha <vbucha@codeaurora.org>