Ok, then why not build it yourself?
Is not that hard...
https://openwrt.org/docs/guide-developer/build-system/install-buildsystem
https://openwrt.org/docs/guide-developer/build-system/use-buildsystem
To switch to kernel 4.14 you have to modify only the top Makefile of the lantiq target.
Modify KERNEL_PATCHVER:=4.9 to KERNEL_PATCHVER:=4.14 and build the image with all packages you need...
Also if you are not that skilled, this should give you a custom image in a couple of hours...
Greets