tests: shell: limit build only config tests

Limit build_only config tests to one platform.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

tests/subsys/shell/shell/testcase.yaml

@@ -1,79 +1,107 @@
 common:
   tags: shell
-  min_ram: 32
-  integration_platforms:
-    - native_sim
-
 tests:
   shell.core:
     min_flash: 64
-
+    min_ram: 32
+    integration_platforms:
+      - native_sim
+  # all tests below are just a build test verifying config options, it fails if run
+  # and can be covered with one platform.
   shell.min:
     min_flash: 32
     extra_args: CONF_FILE=shell_min.conf
+    platform_allow:
+      - mps2/an385
     build_only: true
 
   shell.min_cmds:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_cmds.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_cmds_all:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_cmds_all.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_cmds_resize:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_cmds_resize.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_cmds_select:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_cmds_select.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_colors:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_colors.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_help:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_help.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_help_all:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_help_all.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_history:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_history.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_log_backend:
     min_flash: 64
     extra_args: CONF_FILE=shell_min_log_backend.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_metakeys:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_metakeys.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_tab:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_tab.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_tab_auto:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_tab_auto.conf
     build_only: true
+    platform_allow:
+      - mps2/an385
 
   shell.min_wildcards:
     min_flash: 32
     extra_args: CONF_FILE=shell_min_wildcards.conf
     build_only: true
+    platform_allow:
+      - mps2/an385