power: qpnp-fg-gen3: prepare for QNOVO TTF

Micro resolution and 64-bit division is unnecessary; use milli
resolution instead. Measuring the IBATT and VBATT periodically during
sleep is necessary for accuracy. Don't clear the IBATT and VBATT buffers
on suspend to account for the higher charge current during suspend.
Prime the IBATT and VBATT buffers with 10 samples to get a more accurate
first estimate. Introduce a ttf mode to separate the differences in the
QNOVO version of TTF.

Change-Id: Ibc591dd5d38d4bbb712d8906755040d59181f008
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>