power: pmic-voter: Increase maximum client capacity

Currently, a pmic voter supports a maximum number of 16 clients.
However, this is not sufficient for some voters which have more
than 16 clients. Hence, increase the maximum client capacity of
a voter to 32.

Change-Id: If9776fc6646c868fa3a8cd1520963c7f51aa1e16
Signed-off-by: Umang Agrawal <uagrawal@codeaurora.org>