remove 'elbe create' and unused make templates

In the past 'elbe create' was used to generate a virtual machine with the
same architecture as the target.

Nowadays 'elbe init' is used to generate an amd64 buildenvironment. Within
this environment the target images are generated with 'elbe buildchroot'
that basicly uses debootstrap + python-apt.

Signed-off-by: Manuel Traut <manut@linutronix.de>