ARM: dts: msm: update supply-min-voltage of dsi phy supply for Blair

In Blair target, the MX Rail supports till SVSL1 mode whereas
in Holi target it’s Nominal. Change the qcom,supply-min-voltage
of the dsi phy 0p9 power supply to SVSL1.

Change-Id: If6bfe3021f27ce844783b586b42ef0edb7db157f