power: bcl: Check battery state of charge for frequency mitigation

When BCL monitoring is disabled, the SoC monitoring state is reset
but the last read value is not reset. During BCL frequency mitigation,
it always checks the last read soc value against configured BCL soc
threshold. This will allow the SoC based frequency mitigation to be
active, even when BCL is disabled. Use BCL soc state instead of
the last read battery SoC value to place soc frequency mitigation.

Change-Id: I2b1a171b0bc00cbb4f7029c8de2aaa4817573b49
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>