platform/x86: ISST: Account for increased timeout in some cases

platform/x86: ISST: Account for increased timeout in some cases

In some cases when firmware is busy or updating, some mailbox commands
still timeout on some newer CPUs. To fix this issue, change how we
process timeout.

With this change, replaced timeout from using simple count with real
timeout in micro-seconds using ktime. When the command response takes
more than average processing time, yield to other tasks. The worst case
timeout is extended upto 1 milli-second.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20210330220840.3113959-1-srinivas.pandruvada@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>