tests: drivers: build_all: video: Add test case for smartdma

Add built-only test case for smartdma driver

Signed-off-by: Phi Bang Nguyen <phibang.nguyen@nxp.com>

Author: ngphibang

tests/drivers/build_all/video/testcase.yaml

@@ -19,3 +19,6 @@ tests:
     platform_allow:
       - mimxrt1170_evk/mimxrt1176/cm7
       - mimxrt1170_evk@B/mimxrt1176/cm7
+  drivers.video.mcux_smartdma.build:
+    platform_allow:
+      - frdm_mcxn947/mcxn947/cpu0