Revert "ARM: dts: msm: Remove TCSR_QUSB2_PHY_CLAMP_DIG_N_1P8 for SDM660"

Commit c20c74d4 ("ARM: dts: msm: Remove TCSR_QUSB2_PHY_CLAMP_DIG_N_1P8
for SDM660") is added to remove enabling/disabling clamp during
disconnect/connect. But it is required to enable clamp input to QUSB2PHY,
whenever 0.9V LDO is collapsed. Hence revert the change to add dtsi
property for enable/disable clamp.

Change-Id: I12009bd56d214499a73f7ea3e73d1c979c107ac9
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>