power: qpnp-smbcharger: fix usage of un-initialized variable

Initialize variables to valid values before using them in charger
drivers.
Also Enable SMBCHG restart workaround for PMI8950.

CRs-Fixed: 996609
Change-Id: I3a9f2ef71b657b3926ccd2325585c9b2a4edead9
Signed-off-by: Vamshi Krishna B V <vbv@codeaurora.org>