cmake: bootloader: Only include dummy values when testing

Only includes dummy values for the secure boot bootloader when
partition manager is disabled

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

subsys/bootloader/CMakeLists.txt

@@ -8,11 +8,16 @@ add_subdirectory(bl_boot)
 
 zephyr_include_directories(include)
 
-if (NOT IMAGE_NAME AND NOT SYSBUILD)
+if(NOT IMAGE_NAME AND (NOT SYSBUILD OR (SYSBUILD AND NOT CONFIG_PARTITION_MANAGER_ENABLED)))
   message(WARNING "Building bootloader without associated application. "
           "Dummy values will be used for partition configuration."
-          "The idiomatic way of including the immutable bootloader is to set "
-          "the configuration 'CONFIG_SECURE_BOOTLOADER=y' in your applications "
-          "'prj.conf'.")
+          "Building bootloader without associated application. ")
+
+  if(NOT SYSBUILD)
+    message(WARNING "The idiomatic way of including the immutable bootloader is to set "
+            "the configuration 'CONFIG_SECURE_BOOTLOADER=y' in your applications "
+            "'prj.conf'.")
+  endif()
+
   zephyr_include_directories(include/dummy_values/)
 endif()