Current BSP radio API does not allow the configuration of the transmit power. This issue aims at extending the API such that upper layers can pass the desired output power in dBm that will be matched to the "best available" setting of the radio chip.
With user requested power as `power`, we define "best available" as:
if `power` is greater than the max supported output power of the chip: configure max supported output power.
if `power` is lower or equal than the max supported output power of the chip: configure the output power of the chip that is greater than or equal than `power`
This feature is needed to support the integration of openwsn with OpenBenchmark.