Instead of having to rely on the kernel command line, we convert all the
kernel functionality in question into modules and rely on the auto-load
feature in the kernel and modprobe to add options at load time.
The fb_tunnels setting is a net core setting, for that we use sysctl.
This commit also syncs the kernel config between our two main archs,
disabling DRM and SOUND for the Amd64 build as a spin-off.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>