ARM: dts: msm: Add usb_hs_phy_sleep_clk to USB HS PHY device

The gcc_usb2_hs_phy_sleep_clk is better suited to be
handled by the USB HS PHY driver rather than by the SSUSB
controller. Add a device tree clock property to the HSPHY
device.

Change-Id: Ie6499bcca8dc331e92adb9155ddf53d0e6d28fd3
Signed-off-by: Jack Pham <jackp@codeaurora.org>