trace: refine reschedule time for dma trace

It is a simple fix for trace buffer overflowing at the boot
up time or debug mode FW. At boot up time, there are many trace
events for topology loading in very short time, the trace buffer
needs to be scheduled ASAP. 5us is the shortest time works on
every platforms.

Signed-off-by: Rander Wang <rander.wang@linux.intel.com>
4 files changed