One Kernel For All

We are already there for 64-bit ARM and 32-bit ARMv7, distros only ship one mainline Linux kernel image for all devices. Of course for non-mainline devices its a different situation, you need one Linux kernel image per device, but most generic distros outside the hardware-specific distros do not support non-mainline devices.

I very much doubt distros would add a mobile variant just for one config option. Distros do not want to have multiple images for different use-cases, they want one Linux kernel image that boots on any hardware and works for any use-case. I think they might accept a boot-time option though if automatic behaviour selection at boottime or runtime really isn't going to be implemented, a boot option is still a bit of a hack though.

At least that is the situation for Debian arm64 and armhf. For arm64 it has a single image for devices and also a -cloud image that contains a cut-down image with only cloud related config to reduce the image size and boot time. For armhf Debian ships two "multiplatform" kernel flavours; with and without LPAE. Also -rt images for both because RT isn't able to be enabled/disabled at boot or runtime.

https://www.debian.org/releases/stable/arm64/ch02s01.en.h...
https://wiki.debian.org/DebianKernel/ARMMP

$ apt-cache showsrc linux-signed-arm64 | grep '^ linux-image'
linux-image-5.18.0-2-arm64 deb kernel optional arch=arm64
linux-image-5.18.0-2-cloud-arm64 deb kernel optional arch=arm64
linux-image-5.18.0-2-rt-arm64 deb kernel optional arch=arm64
linux-image-arm64 deb kernel optional arch=arm64
linux-image-cloud-arm64 deb kernel optional arch=arm64
linux-image-rt-arm64 deb kernel optional arch=arm64
$ apt-cache showsrc linux | grep 'arch=armhf' | grep '^ linux-image' | grep -v -- '-dbg'
linux-image-5.18.0-2-armmp deb kernel optional arch=armhf profile=!pkg.linux.nokernel,!pkg.linux.quick,!stage1
linux-image-5.18.0-2-armmp-lpae deb kernel optional arch=armhf profile=!pkg.linux.nokernel,!pkg.linux.quick,!stage1
linux-image-5.18.0-2-rt-armmp deb kernel optional arch=armhf profile=!pkg.linux.nokernel,!pkg.linux.quick,!stage1
linux-image-armmp deb kernel optional arch=armhf profile=!pkg.linux.nokernel,!pkg.linux.nometa,!pkg.linux.quick,!stage1
linux-image-armmp-lpae deb kernel optional arch=armhf profile=!pkg.linux.nokernel,!pkg.linux.nometa,!pkg.linux.quick,!stage1
linux-image-rt-armmp deb kernel optional arch=armhf profile=!pkg.linux.nokernel,!pkg.linux.nometa,!pkg.linux.quick,!stage1