.travis.yml: powerpc: Build mpy-cross.
.travis.yml: powerpc: Build mpy-cross.

Change-Id: I17e24e3fe216bc0b68e0580df6c56d4e31163800
Signed-off-by: Paul Sokolovsky <9dc5061f178bb11813e14f1ed02ba27eaf21fa5d@users.sourceforge.net>

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython