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

@@ -1242,6 +1242,9 @@ Nanopb
 LVGL
 ****
 
+* Added definition of ``LV_ATTRIBUTE_MEM_ALIGN`` so library internal data structures can be aligned
+  to a specific boundary.
+
 zcbor
 *****
 
@@ -1263,6 +1266,9 @@ 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.
+
 Issue Related Items
 *******************