usb: gadget: f_uvc: change endpoint allocation in uvc_function_bind()

when call uvc_function_bind(), gadget still have no connection speed,
just follow other gadget function, use fs endpoint descriptor to allocate
a video endpoint, remove gadget_is_{super|dual}speed() API call.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-4-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>