Enabling SMP on the xway target results in two issues:
* some danube chipset-based devices fail on boot,
* on devices based on the arx100 chipset, enabling smp
results in a degradation of NAT performance.
After these two issues are fixed, SMP can be re-enabled.
This reverts commit 084c20f6c5.
Fixes: #13934
Fixes: #14283
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>