doc: release notes: Include LoRa in major features

Add LoRa to the major feature list of 2.2.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

doc/releases/release-notes-2.2.rst

diff --git a/doc/releases/release-notes-2.2.rst b/doc/releases/release-notes-2.2.rst
index cdb9152..768009a 100644
--- a/doc/releases/release-notes-2.2.rst
+++ b/doc/releases/release-notes-2.2.rst
@@ -11,6 +11,8 @@
 
 * We added initial support for 64-bit ARMv8-A architecture (Experimental).
 * CANopen protocol support through 3rd party CANopenNode stack
+* LoRa support was added through integration of the Semtech LoRaWAN endpoint
+  stack and addition of a new SX1276 LoRa modem driver.
 
 The following sections provide detailed lists of changes by component.