power: smb135x-charger: Vote for USB data-line pull-up regulator

USB data lines should be at appropriate voltage level for SMB135x
hardware to perform the automatic source detection.
Add support to vote for USB data line pull-up regulator, this regulator
is required to be kept always-on to guarantee that the D+ line is at the
right voltage.

CRs-Fixed: 779207
Change-Id: I3cee9c7ec0481cb537c578a499d3dd53968b2cd4
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>