power: battery-gauge: remove mutex lock while reading current limit

power: battery-gauge: remove mutex lock while reading current limit

Removing mutex lock while reading input current limit.
mutex lock cuasing dead lock situation in suspend resume test.
while reading input current limit, mutex lock is not required
as no parameter is updated in this api.

Bug 200118347

Change-Id: I1db7adbe545eabfbfa4172d42b13571669ef62c7
Signed-off-by: Venkat Reddy Talla <vreddytalla@nvidia.com>
Reviewed-on: http://git-master/r/763994
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>