[kde-plasma] Change lidAction to turn off screen, instead of the default sleep, which do not work on must devices anyway

Had forgotten to remove swapiness config that was not working out

Switch to the linux-rpi4-mainline kernel, which is the 5.4 branch from Raspberry Pi, instead of using pure mainline.
Some stuff, like v3d, still does not work right on mainline, so using the rpi tree directly should enable that.

Signed-off-by: Dan Johansen <strit@manjaro.org>

[oc2][on2][pbpro][rock64][rpi3][rpi4][vim1][vim2] add bootsplash packages. Only enabled on select devices