update CHANGELOG for final release

Author: sainoe

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 Add an entry to the unreleased section whenever merging a PR to main that is not targeted at a specific release. These entries will eventually be included in a release.
 
+## v2.2.0-provider-lsm
+
 ### Cryptographic verification of equivocation
 * New feature enabling the provider chain to verify equivocation evidence on its own instead of trusting consumer chains, see [EPIC](https://github.com/cosmos/interchain-security/issues/732).