micropython: new package

Micro Python is a lean and fast implementation of the Python 3
programming language that is optimised to run on a microcontroller.

[Thomas: fix minor typo in Config.in noticed by Vicente.]

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Tested-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>