msm: ipa: allow configuration of timer granularity

Add an API to configure aggregation and EOT coalescing
timer granularity. This option is added as part of the
new IPA2.5 core.

Change-Id: I35733e748994e315e6dc7b91bc4540899fbe9a56
Signed-off-by: Ravit Katzav <rkatzav@codeaurora.org>