Update version of meta-raspberrypi to support the
new model Raspberry Pi 3 B+. Now AGL images built
for machine raspberrypi3 will work on both Raspberry
Pi 3 Model B and Raspberry Pi 3 Model B+.
Bug-AGL: SPEC-1431
Change-Id: Ia0490aeb56beb9a957e31acd3957f97cb9139e7d Signed-off-by: Leon Anavi <leon.anavi@konsulko.com>