usb: gadget: f_uac2: Add speed names to bInterval dbg/warn

Add speed names for better clarity of dgb/warn messages from max packet
size/bInterval checks.

Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com>
Link: https://lore.kernel.org/r/20220127114331.41367-5-pavel.hofman@ivitera.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>