slimbus: Reduce slimbus run-time auto-suspend interval

Reduce the slimbus controller's run-time autosuspend interval to improve
energy efficiency during the audio silence period.

CRs-Fixed: 2197936
Change-Id: Iabb0866a9f9469afb68c11de7798830cda2e962f
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>