phy: qualcomm: usb-hs-28nm: Prepare clocks in init

The AHB clock must be on for qcom_snps_hsphy_init() to be able to write
the initialization sequence to the hardware, so move the clock
enablement to phy init and exit.

Fixes: 67b27dbe ("phy: qualcomm: Add Synopsys 28nm Hi-Speed USB PHY driver")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>