power: qpnp-bms: Clear fcc_count if battery removal is detected

The last_fcc_update_count tracks the updated location of the
FCC data array. Reset this variable if battery removal is
detected.

While at it, avoid FCC updates from userspace after the intial
set of FCC data tuple. Such a condition can occur if userspace
reboots/restarts.

Change-Id: I7a0eb70f73241874dab6b4c6b39795d18509f0cd
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>