scsi: ufs: change the clock scaling polling period and up threshold

We have noticed that UFS load based clock scaling is ramping up to highest
frequency during low power usecases but never scales back to lower
frequency during the remaining usecase run period. This increases the
oveall power consumption for a given low power usecase. We analyzed UFS
data transfer pattern for different low power usecases and updated clock
scaling polling period & up threshold which helps with power numbers
without affecting performance numbers.

Change-Id: I74cf8a1f07d1b1a0ac112f28fc98a8a82cac1d28
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>