ci: mynewt: Enable Mynewt specific tests

This allows to run Mynewt bootserial tests in CI.

Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl>
diff --git a/ci/mynewt_install.sh b/ci/mynewt_install.sh
index abadfb3..ea7e753 100755
--- a/ci/mynewt_install.sh
+++ b/ci/mynewt_install.sh
@@ -57,9 +57,15 @@
     done
 }
 
+native_test_setup() {
+    sudo apt-get update
+    sudo apt-get install -y gcc-multilib
+}
+
 mkdir -p $HOME/bin
 export PATH=$HOME/bin:$PATH
 
 install_newt
 shallow_clone_mynewt
 arm_toolchain_install
+native_test_setup