msm: ipa: enable clock scaling by default

Enable IPA clock scaling feature by default.
IPA clock frequency is set according to RM performance setting.

Change-Id: Icf226ab9a58b34876469e0208eeb6859f1b21a0e
Acked-by: Ady Abraham <adya@qti.qualcomm.com>
Signed-off-by: Ravit Katzav <rkatzav@codeaurora.org>