power: qpnp-fg: Remove the otp config code in fg_config_access

Since the default value of the OTP_CFG1 register is 0x0, writing
0x0 to it serves no purpose. So remove this code. Also, since the
otp variable is not used anymore, remove it from the function
signature and update all function calls accordingly.

CRs-Fixed: 900667
Change-Id: I42d9ed8f2418d9faed9ab35d8f044bc4a91b131e
Signed-off-by: Devesh Jhunjhunwala <deveshj@codeaurora.org>