Until now only the BMS system was using the ccadc so there was
no need to create a separate ccadc driver.
However we can run in a configuration with BMS disabled
and clients won't be able to read battery current via ccadc.
Separate the ccadc from the bms, this change in is preparation
to add a ccadc api to read the battery current.
Change-Id: Ib96b146d91d01d196df9291eb23432cd430db4d0
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
82d939848f