Add a platform cleanup hook before starting the kernel. The openfirmware
and PXE loaders clean up their network stack there, while the other
loaders currently do nothing.
This closes ticket #6166
Change-Id: I34765892dfd9b2310c6af97c9ff7d414afae49e5
Reviewed-on: https://review.haiku-os.org/c/50
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
e1b41d44a3