Affected boards: NRF51_DK, NRF52_DK, Beetle. This change is temporary and
will be overwritten by RTX update. It's necessary for the boards to pass
updated tests.
+ mbed RTx setings for nRF52840
fix build of test for NRF52840
+ few sdk's missing filess
- few sdk's unvanted files
corect mbed HAL implementation to changes made in sdk v13