This commit adds basic support for nrf52811 in the arch SoC, dts
and nrfx folders.
The nRF52811 is a Bluetooth 5.1 Direction Finding SoC with comprehensive
protocol support.
The nRF52811 SoC is capable of the latest features of Bluetooth 5.1,
the most prominent being Direction Finding.
The radio in the nRF52811 SoC has comprehensive protocol capabilities,
including Bluetooth 5.1 Directing Finding, all Bluetooth 5 features,
802.15.4, Thread, Zigbee, ANT and 2.4 GHz proprietary.
It has 4 dBm TX power and has been optimized to offer the best RX
sensitivity of all SoCs in the nRF52 series.
Signed-off-by: Jakub Rzeszutko <jakub.rzeszutko@nordicsemi.no>