usb: gadget: remove max support speed info in bind operation

Take ecm_bind() for example, it call gadget_is_{*}speed() API to show
gadget max support speed, it is not much help, remove the API usage here
is safe.

Similar change apply to acm,eem,loopback,ncm,obex,rndis,serial,
sourcesink,subset functions.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-8-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>