battery: remove 20ms delay for running AICL

The driver waits 20mS after setting ICL to a step lower
than settled value before increasing it back to the effective
value. That 20mS delay is not required and causes PR_SWAP compliance
tests to fail. Remove it.

Change-Id: I8bd43a885c554df3590499ddf2a219e816e28734
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>