ztest: fix ztest_1cpu_user_unit_test()

The start/stop functions do a whole pile of supervisor-
only stuff; resolve this by making them ztest-specific
system calls.

Fixes: #20927

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ca9302e..1df92c5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -557,6 +557,10 @@
   set(SYSCALL_INCLUDE_DIRECTORY --include ${APPLICATION_SOURCE_DIR})
 endif()
 
+if(CONFIG_ZTEST)
+  set(SYSCALL_ZTEST_DIRECTORY --include ${ZEPHYR_BASE}/subsys/testsuite/ztest/include)
+endif()
+
 add_custom_command(
   OUTPUT
   ${syscalls_json}
@@ -565,6 +569,7 @@
   ${ZEPHYR_BASE}/scripts/parse_syscalls.py
    --include          ${ZEPHYR_BASE}/include        # Read files from this dir
   ${SYSCALL_INCLUDE_DIRECTORY}
+  ${SYSCALL_ZTEST_DIRECTORY}
   --json-file        ${syscalls_json}              # Write this file
   DEPENDS ${syscalls_subdirs_trigger} ${PARSE_SYSCALLS_HEADER_DEPENDS}
   )