tsif: Improve workaround for DMA bug

During tsif stress tests it was reported that the dma flush caused by
calling action_close() is sometimes unrecoverable. The root cause is
stopping the tsif while a read by the dma of the tsif FIFO is in
progress. The previous workaround relied on closing the tsif GPIOs
to stop incoming data to the tsif, then add a delay to allow the
dma to complete all outstanding transactions. A customer still reported
seeing the dma issue. The reason the issue was still happening is due to
the call of gpio API (request/free) which was done on pins not configured
to act as GPIOs. Doing so caused tsif interface not to be closed properly.

Per gpio-mux documentation, pins with function configured as non-gpio
may suffer from un-expected behavior when calling gpio API, these calls
were removed. The delay after closing tsif interface was enlarged to better
cope with low bitrate streams.

Change-Id: I67828c9ad946072a2a925a1d55f35c730a52170c
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>