@horuxan I think you use wrong version of kernel incompatible with code source, wich repo and version of ubuntu touch did you use ? wich repo and versionof device tree and kernel did you use?
Because by default ub-5.1 compile fine after few errors can be easily fixed.
ub-6.0 its difficult to adopte with kernel and device tree.
If you use ub-5.1 from ubports (recommended) then just use cm-12.1 device tree and kernel