usb: chipidea: usb2: remove unneeded semicolon

Fix the following coccicheck warning:

drivers/usb/chipidea/ci_hdrc_usb2.c:75:28-29: Unneeded semicolon

Fixes: c2de37b3 ("usb: chipidea: usb2: make clock optional")
Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>