ARM: dts: mdm: Use qcom,qusb-phy-init-seq with QUSB PHY on mdm9640

QUSB PHY driver only has support to use qcom,qusb-phy-init-seq based
initialization sequence on msm-3.18 kernel whereas current mdm9640
dtsi is using qcom,qusb-tune which is only supported on msm-3.10 kernel.
Due to this, QUSB PHY is not initialized as expected. This results into
multiple USB enumeration and data stall issues in USB high-speed mode.
Fix those issues by using qcom,qusb-phy-init-seq with required
<value, offset> pairs as initialization sequence.

CRs-Fixed: 1025088
Change-Id: I339ceeb4d484abf261012549e0b04d56cac3ffd3
Signed-off-by: Mayank Rana <mrana@codeaurora.org>