doc: release-notes: Add TF-M release notes

Adds release notes for Zephyr 3.2 related to TF-M.

Signed-off-by: Kevin Townsend <[email protected]>

Author: microbuilder

doc/releases/release-notes-3.2.rst

@@ -639,9 +639,14 @@ HALs
 MCUboot
 *******
 
-Trusted Firmware-m
+Trusted Firmware-M
 ******************
 
+* Allow enabling FPU in the application when TF-M is enabled.
+* Added option to exclude non-secure TF-M application from build.
+* Relocated ``mergehex.py`` to ``scripts/build``.
+* Added option for custom reset handlers.
+
 Documentation
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