Zephyr 2.2.1

This is a maintenance release for Zephyr 2.2 with fixes.

Security Vulnerability Related

The following security vulnerabilities (CVE) were addressed in this release:

These GitHub issues were addressed since the previous 2.2.0 tagged
release:

#23494 - Bluetooth: LL/PAC/SLA/BV-01-C fails if Slave-initiated Feature Exchange is disabled
#23485 - BT: host: Service Change indication sent regardless of whether it is needed or not.
#23482 - 2M PHY + DLE and timing calculations on an encrypted link are wrong
#23070 - Bluetooth: controller: Fix ticker implementation to avoid catch up
#22967 - Bluetooth: controller: ASSERTION FAIL on invalid packet sequence
#24183 - [v2.2] Bluetooth: controller: split: Regression slave latency during connection update
#23805 - Bluetooth: controller: Switching to non conn adv fails for Mesh LPN
#24086 - Bluetooth: SMP: Existing bond deleted on pairing failure
#24211 - [v2.2.x] lib: updatehub: Not working on Zephyr 2.x
#24601 - Bluetooth: Mesh: Config Client's net_key_status pulls two key indexes, should pull one.
#25067 - Insufficient ticker nodes for vendor implementations
#25350 - Bluetooth: controller: Data transmission delayed by slave latency
#25483 - Bluetooth: controller: split: feature exchange not conform V5.0 core spec
#25478 - settings_runtime_set() not populating bt/cf
#25447 - cf_set() returns 0 when no cfg is available