boards: nrf52811_pca10056: Enable nRF 802.15.4 driver by default

nrf52811_pca10056 board should enable nRF 802.15.4 radio driver
automatically when 802.15.4 subsystem is enabled, as other Nordic
802.15.4-compliant boards do.

Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
2 files changed