power: qpnp-fg-gen4: add support for capacity learning and cycle counter

Capacity learning and cycle counter algorithms are supported
through fg-alg.c. Add the necessary initialization and callback
functions to GEN4 FG driver to support those algorithms.

Change-Id: If071bf02cc6ddcedbc7361c8a02f23bd1ca95b5c
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>