drivers: thermal: bcl-pmic5: Add support for BCL-LMH Level interrupt

BCL Peripheral sends LMH levels as interrupt and these interrupts can be
sent for multiple reasons like Vbat or Ibat condition. Add support in the
BCL driver to read the interrupt status register and notify the
appropriate thermal zones on receiving the interrupt.

Change-Id: Ifb0608c416fd2943d8325428e9e696a29cf7e364
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>