samples: userspace: set integration_platforms to mps2_an385

Set integration_platforms on these samples to just mps2_an385.
This should be sufficient to make sure these tests build and run.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
diff --git a/samples/userspace/hello_world_user/sample.yaml b/samples/userspace/hello_world_user/sample.yaml
index 4d76011..221ae4d 100644
--- a/samples/userspace/hello_world_user/sample.yaml
+++ b/samples/userspace/hello_world_user/sample.yaml
@@ -3,6 +3,8 @@
     Zephyr application
   name: hello world user
 common:
+    integration_platforms:
+      - mps2_an385
     tags: introduction
     harness: console
     harness_config:
diff --git a/samples/userspace/prod_consumer/sample.yaml b/samples/userspace/prod_consumer/sample.yaml
index 7c5c647..c831da3 100644
--- a/samples/userspace/prod_consumer/sample.yaml
+++ b/samples/userspace/prod_consumer/sample.yaml
@@ -2,6 +2,8 @@
   description: userspace producer-consumer example
   name: producer-consumer
 common:
+    integration_platforms:
+      - mps2_an385
     tags: userspace
     harness: console
     harness_config:
diff --git a/samples/userspace/shared_mem/sample.yaml b/samples/userspace/shared_mem/sample.yaml
index f152b51..faa596b 100644
--- a/samples/userspace/shared_mem/sample.yaml
+++ b/samples/userspace/shared_mem/sample.yaml
@@ -3,6 +3,8 @@
     example application
   name: protected memory
 common:
+    integration_platforms:
+      - mps2_an385
     tags: userspace
     harness: console
     harness_config: