manifest: update lvgl

Pull latest changes from the LVGL module: migration to <zephyr/...>
includes.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

Author: gmarull

west.yml

@@ -168,7 +168,7 @@ manifest:
       revision: 12019623bbad9eb54fe51066847a7cbd4b4eac57
       path: modules/lib/loramac-node
     - name: lvgl
-      revision: f6541c6015662715d331a5cf71216707122e4e22
+      revision: 9955c3e1e4f361884e938dc016da5a715a4527fe
       path: modules/lib/gui/lvgl
     - name: lz4
       revision: 8e303c264fc21c2116dc612658003a22e933124d