defconfig: msm9625: Enable fixed regulator driver

SDC2 has a fixed voltage regulator that can be enabled
or disabled. Enable the fixed regulator driver in order
to control this regulator.

Change-Id: I1000675fe24f164802cfb15eb48af3e1bf8efa63
Signed-off-by: Oluwafemi Adeyemi <aadeyemi@codeaurora.org>