doc: release: 4.0: Add lvgl notes

Add release notes section about lvgl and the added sample.

Signed-off-by: Fabian Blatz <[email protected]>

Author: faxe1008

doc/releases/release-notes-4.0.rst

@@ -1080,6 +1080,9 @@ Nanopb
 LVGL
 ****
 
+* Added definition of ``LV_ATTRIBUTE_MEM_ALIGN`` so library internal data structures can be aligned
+  to a specific boundary.
+
 zcbor
 *****
 
@@ -1101,6 +1104,9 @@ Tests and Samples
   explicitly run in native_posix now run in :ref:`native_sim<native_sim>` instead.
   native_posix as a platform remains tested though.
 
+* Added :zephyr:code-sample:`smf_calculator` sample demonstrating the usage of the State Machine framework
+  in combination with LVGL to create a simple calculator application.
+
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