ASoC: msm: increase slimbus channel FIFO watermark value

Default FIFO watermark value is set as 8 bytes. Observed data skipping
randomly at higher sample rates with default watermark value. Increase
the watermark value to 16 bytes to avoid data loss.

Change-Id: Ic595f62f243b6087ceb2dc61089f957b6a6f8121
Signed-off-by: Vidyakumar Athota <vathota@codeaurora.org>