Build: Fix tf-m-example-ns-app build for RP2350

The RP2350 platform NS build requires an ASM compiler, so ASM must be
specified as a language used by the project

Change-Id: Ifcdd7c30e15f215161f9510ee26c46d6829b2a22
Signed-off-by: William Vinnicombe <william.vinnicombe@raspberrypi.com>
(cherry picked from commit e3559431f8c0cd3d9505f7c1d4e8597c212614a3)
diff --git a/examples/tf-m-example-ns-app/CMakeLists.txt b/examples/tf-m-example-ns-app/CMakeLists.txt
index 1e93790..19afc19 100644
--- a/examples/tf-m-example-ns-app/CMakeLists.txt
+++ b/examples/tf-m-example-ns-app/CMakeLists.txt
@@ -30,7 +30,7 @@
 
 include(${TFM_TOOLCHAIN_FILE})
 
-project("TF-M Example"  LANGUAGES C)
+project("TF-M Example"  LANGUAGES C ASM)
 tfm_toolchain_reload_compiler()
 
 # The exported TF-M interfaces