usb: dwc3: gadget: increase tx fifo size for ss isoc endpoints

Improve performance of isoc transfers in superspeed by increasing the
number of possible endpoints available, matching that of what was
configured for bulk transfers.

Signed-off-by: Dan Vacura <w36195@motorola.com>
Link: https://lore.kernel.org/r/20220420183338.445622-1-w36195@motorola.com


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