usb: dwc3: Don't call clk_bulk_disable_unprepare() twice

devm_clk_bulk_get_all_enabled() is used in the probe, so
clk_bulk_disable_unprepare() should not be called explicitly in the remove
function.

Fixes: e0b6dc00 ("usb: dwc3: add generic driver to support flattened")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>