Move the kernel versions and hash to dedicated files.
This makes kernel bump quicker and fix some annoying
problem with rebasing when multiple kernel bump are proposed.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
[Rebased on top of current master]
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
(cherry picked from commit 0765466a42)
Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
[Rebased on top of current openwrt-21.02]
