"Mixin" layer for adding latest Linux kernel LTS into the Yocto Project LTS.

Currently it adds Linux 6.1 LTS on top of the "Kirkstone" 4.0 Yocto Project LTS.
At the time Kirkstone was released in April 2022, kernel 6.1 was not out yet and
officially Kirkstone supports 5.15 kernel LTS. This thin special-purpose mixin
layer is meant to address this issue by backporting linux-yocto kernel recipes
(and corresponding out-of-tree kernel modules) from a latest stable release of
openembedded-core, i.e. Langdale, Mickledore, etc.

If the new kernel version is not picked up automatically, you may want to add
the following line to your distro config or local.conf:
PREFERRED_VERSION_linux-yocto ?= "6.1%"

Maintainers:
Denys Dmytriyenko <denis@denix.org>