usb: gadget: composite: cleanup function config_ep_by_speed_and_alt()

When call this function, gadget already have working speed, if it is
USB_SPEED_SUPER_PLUS, in theroy gadget_is_superspeed_plus() checking
should be true, so there is no need to call it. it is same for other
working speed.

Remove all gadget_is_{*}speed_plus() API call to clean it up.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-7-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>