The target has testing support for kernel 5.4 for quite a while,
compiles fine for all devices, and has been run-tested on Asus
RT-N56U successfully.
Let's set it to kernel 5.4 by default to increase the audience
before an 20.xx stable branch.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Tested-by: Eneas U de Queiroz <cotequeiroz@gmail.com> [Asus RT-N56U]
RT3x5x seems to work fine with kernel 5.4. Set the default kernel
version to 5.4 to bring this to a broader audience.
Since 4 of 6 targets are on kernel 5.4 now, invert the kernel
version setup logic in Makefile/target.mk files.
Tested on ZyXEL Keenetic.
Signed-off-by: Alexey Dobrovolsky <dobrovolskiy.alexey@gmail.com>
[invert version setup logic]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
