Integrate meta-guf-distro/fix-fngsystem-release-artefacts-list

Commit: https://gitlab.com/garz-fricke/yocto/layers/meta-guf-distro/-/commit/81d6c95dbcffa48bb61c91eff0a7dde63bd0863b

imx8mguf:release artefacts: Fix append syntax so all needed artefacts are copied

Use _append_mx8 instead of +=, as the previous way didn't really appended but overwrote the variable content. This leaded to some missing files in the release.

default.xml

@@ -23,7 +23,7 @@
   <project name="meta-freescale"          revision="0173d3f8d0cbf7844a4d23bc3fb30144abc914bb"  remote="fslc"  path="sources/meta-freescale"           />
   <project name="meta-freescale-distro"   revision="5d882cdf079b3bde0bd9869ce3ca3db411acbf3b"  remote="fslc"  path="sources/meta-freescale-distro"    />
   <project name="layers/meta-guf-machine" revision="d7ce19734ae874dfe4a277077a0a1cca380f2c5e"  remote="guf"   path="sources/meta-guf-machine"         />
-  <project name="layers/meta-guf-distro"  revision="77406f583040c65b6c645d000420a9143a470f0a"  remote="guf"   path="sources/meta-guf-distro"          />
+  <project name="layers/meta-guf-distro"  revision="81d6c95dbcffa48bb61c91eff0a7dde63bd0863b"  remote="guf"   path="sources/meta-guf-distro"          />
   <project name="config"                  revision="c4f5341f890eee7475927d6062204276471e0c76"  remote="guf"   path=".conf">
          <linkfile dest="setup-environment" src="setup-environment"/>
   </project>