ARM: dts: msm: Update ref_clk related address for MSM8996

On MSM8996, it is required to turned ON and OFF ref_clk explicitly
before performing QUSB PHY reset and after QUSB PHY initialization
respectively. Hence add ref_clk address value here for QUSB PHY
to perform the same.

Change-Id: I5d3afc5204ccd75fda1f7c50e67151bdd77d699f
Signed-off-by: Mayank Rana <mrana@codeaurora.org>