CHANGELOG.md: Add NXP S32G3 and SCMI-SMC layer support mentions

Signed-off-by: Andrei Cherechesu <andrei.cherechesu@nxp.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>

CHANGELOG.md

@@ -18,6 +18,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Added
  - On Arm:
    - Experimental support for Armv8-R.
+   - Support for NXP S32G3 Processors Family and NXP LINFlexD UART driver.
+   - Basic handling for SCMI requests over SMC using Shared Memory, by allowing
+     forwarding the calls to EL3 FW if coming from hwdom.
  - On x86:
    - xl suspend/resume subcommands.