add preliminary Travis CI support
travis-ci: properly install GNU Tools for ARM Embedded Processors
travis-ci: defer to defconfig

In the future, F9 is expected to support more devices, and it should
be straightforward to enable the build matrix of travis-ci by specifying
the board name.
Merge pull request #77 from ahmedammar/master

ipc: add basic support for L4_Sleep
mpu: move to platform as not all plaforms use ARM's mpu

- Kinetis MCU from FSL uses a different MPU than ARMs