doc: release-notes-4.1: RT106/50 board identifiers

Info in the release notes about changes to the board
identifier of the mimxrt1060_evk and mimxrt1050_evk.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>

Author: decsny

doc/releases/release-notes-4.1.rst

@@ -112,6 +112,10 @@ Boards & SoC Support
 
   * All HWMv1 board name aliases which were added as deprecated in v3.7 are now removed
     (:github:`82247`).
+  * ``mimxrt1050_evk`` and ``mimxrt1060_evk`` revisions for ``qspi`` and ``hyperflash`` have been
+    converted into variants. ``mimxrt1060_evkb`` has been converted into revision ``B`` of
+    ``mimxrt1060_evk``.
+  * Enabled USB, RTC on NXP ``frdm_mcxn236``
 
 * Added support for the following shields: