doc: Add HMAC SHA256 to KMU key types in docs.

Added a release note and update the Supported key types table.

Signed-off-by: Arkadiusz Balys <[email protected]>

Author: ArekBalysNordic

doc/nrf/app_dev/device_guides/nrf54l/cryptography.rst

@@ -263,11 +263,19 @@ The following table lists all key types that can be stored in the KMU, indicatin
      - Yes
    * - ED25519 public key
      - | ``key_type``: ``PSA_KEY_TYPE_ECC_PUBLIC_KEY(PSA_ECC_FAMILY_TWISTED_EDWARDS)``
-       | ``key bits``: 255
+       | ``key_bits``: 255
      - 2
      - No
      - Yes
      - Yes
+   * - HMAC SHA-256 128-bit keys
+     - | ``key_type``: ``PSA_KEY_TYPE_HMAC``
+       | ``key_bits``: 128
+       | ``key_algorithm``: ``PSA_ALG_HMAC(PSA_ALG_SHA_256)``
+     - 1
+     - No
+     - No
+     - Yes
 .. [1] Keys with the Encrypted usage scheme (``CRACEN_KMU_KEY_USAGE_SCHEME_ENCRYPTED``) will require two additional KMU slots to store the nonce and the authentication tag.
 
 Storing keys in KMU

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -68,7 +68,7 @@ Working with nRF54H Series
 Developing with nRF54L Series
 =============================
 
-|no_changes_yet_note|
+* Added HMAC SHA-256 with a 128-bit key type to KMU, as detailed in the :ref:`ug_nrf54l_crypto_kmu_supported_key_types` documentation section.
 
 Developing with nRF53 Series
 ============================