doc: release notes: add missing ARM Board in v2.2 release notes

Adding Si Labs EFM32 Jake Gecko board in the v2.2 release notes.

Signed-off-by: Ioannis Glaropoulos <[email protected]>

Author: ioannisg

doc/releases/release-notes-2.2.rst

@@ -205,6 +205,7 @@ Boards & SoC Support
    * Google Kukui EC
    * NXP i.MX RT1010 Evaluation Kit
    * Silicon Labs EFM32 Giant Gecko GG11
+   * Silicon Labs EFM32 Jade Gecko
    * ST Nucleo F767ZI
    * ST Nucleo G474RE
    * ST Nucleo L152RE