phy: ti: omap-usb2: Fix error handling in omap_usb2_enable_clocks

The corresponding API for clk_prepare_enable is clk_disable_unprepare.
Make sure that the clock is unprepared on exit by changing clk_disable
to clk_disable_unprepare.

Fixes: ed31ee7c

 ("phy: ti: usb2: Fix logic on -EPROBE_DEFER")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220318105748.19532-1-linmq006@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>