webkit: completely drop all machine-specific things

Compiling webkit in a machine specific way doesn't really make sense so we drop everything
related to this and forget about it as fast as possible :)

Open-webOS-DCO-1.0-Signed-off-by: Simon Busch <morphis@gravedo.de>
webos: define DEPLOY_DIR_IMAGE path with separate directory for each MACHINE

* it's easier to find matching rootfs and kernel image

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>