power: qpnp-bms: fix coulomb counter selection

There is a bug in the BMS code right now where reading the coulomb
counter actually reads the shadow coulomb counter and vice versa. Fix
this by correctly specifying the coulomb counter to be read.

Change-Id: Ica703d1e426e595e9ff6cd9fc45bade743740238
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>