usb: gadget: config: remove max speed check in usb_assign_descriptors()

usb_assign_descriptors() usally called inside function bind operation,
and gadget still have no working connection speed, let's support all
speed at this point, it may possible allocate extra memory to store
descriptors, but it is small and acceptable.

Remove gadget_is_{*}speed() API checking to allow support all speed.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-6-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>