In the docs replace the references to native_posix with native_sim
Enable native_sim in the tests, and replace native_posix as integration
platform.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
The nRF52840 DK board target, so far known as nrf52840_pca10056,
is renamed to nrf52840dk_nrf52840.
Its documentation and all references to its name in the tree are
updated accordingly. Overlay and configuration files specific to
this board are also renamed, to match the new board name.
Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
