usb: dwc3: gadget: Fix match_ep callback for NXP UUU tool

usb: dwc3: gadget: Fix match_ep callback for NXP UUU tool

The UUU tool excepts the interrupt-in endpoint to be ep1in, otherwise
it crashes. This is a result of the previous hard-coded EP setup in
drivers/usb/gadget/epautoconf.c which did special-case EP allocation
for SPL builds, and which was since converted to this callback, but
without the special-case EP allocation in SPL part.

This reinstates the SPL part in an isolated manner, only for NXP iMX
SoCs, only for SPL builds, and only for the ep1in interrupt-in endpoint.

Fixes: 1918b8010c32 ("usb: dwc3: gadget: Convert epautoconf workaround to match_ep callback")
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20250319220805.219001-1-marex@denx.de
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>