* HAL: Fixed packet timestamp issue which was "jumping in time" in specific
conditions.
* HAL: Workaround hardware issue when reading 32-bits registers (timestamp, nb
bytes in RX buffer...)
* HAL: Fixed potential endless loop in sx1302_tx_abort() in SPI access fails.
* Packet Forwarder: Added global_conf.json.sx1250.US915 for US915 band
* test_hal_rx: added command line to specify RSSI offset to be applied

* Added missing LICENSE.TXT file
* HAL & Packet Forwarder: added support for sx1250-based reference design for
CN490 region
* Packet Forwarder: disabled beaconing by default

* HAL: Fixed scheduled downlink time precision by taking the tx start delay into
account.
* HAL: Fixed timestamp correction calculation for BW250 & BW500
* HAL: Fixed possible buffer overflow in lgw_receive() function
* HAL: Keep packet received in RX buffer when the buffer allocated to receive
the packets is too small. Remaining packets will be fetched on the next
lgw_receive calls (aligned on SX1301 behaviour).

* Fixed compilation warnings reported by latest versions of GCC
* Reworked handling of temperature sensor
* Clean-up of unused files
* Added instructions and configuration files for packet forwarder auto-start
with systemd
* Added SX1250 radio calibration at startup

HAL accepts to work with both temperature sensors

See merge request LoRa-Gateway/sx1302_hal!1

* Packet Forwarder: Updated TX gain LUT in global_conf.json.sx1250 with proper
calibration

* Initial release for SX1302 CoreCell Reference Design.