package/parted: add a host variant

Useful for for-build scripts to call parted, eg. to generate
partition tables and such automatically.

Since the primary goal is to use parted within scripts, we
do not need readline, so it is forcibly disabled.

Also, it does look unlikely that we need to manipulate LVM
volumes, so we forcibly disable support for the device-mapper.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>