msm: camera: sensor: Add support fo multiple regulator sources

Currently image sensor need single source of the regulator per
category. Some sensor needs extra analog voltage for the functionality,
which require to draw power from multiple voltage regulator sources.
This change extends supports to add multiple voltage sources for
analog voltage.

CRs-Fixed: 2584631
Change-Id: I2d76cfb0fb971758c0d596ffd543aa3926a8886d
Signed-off-by: Jigarkumar Zala <jzala@codeaurora.org>