ARM: dts: msm: Update regulator supply name for msm9625

Update the supply regulator for vdd-dig to use voltage floor corner
regulator.

Remove the underdcore in the regulator supply name defined
in msm-thermal device tree.

CRs-Fixed: 507816
Change-Id: I68387be186d18bdb732450a8eaa577cb6222ad91
Signed-off-by: Jennifer Liu <chihning@codeaurora.org>