USB: OTG: msm: enable the usb_hs_clk only while resetting the HW

usb_hs_clk is used for resetting the USB HW through clk regim. This clock
doesn't required to be enabled for the USB operation. Hence
enable this only while resetting the HW.

Change-Id: I6d46e7dcb41384236dc6a6cfa1bf872bf00c377d
Signed-off-by: Anji jonnala <anjir@codeaurora.org>