tests: arch: arm: move test arm_thread_swap to new ztest API

Migrate the testsuite tests/arch/arm/arm_thread_swap to the
new ztest API.

Signed-off-by: Shaoan Li <shaoanx.li@intel.com>
diff --git a/tests/arch/arm/arm_thread_swap/prj.conf b/tests/arch/arm/arm_thread_swap/prj.conf
index df69638..a618b61 100644
--- a/tests/arch/arm/arm_thread_swap/prj.conf
+++ b/tests/arch/arm/arm_thread_swap/prj.conf
@@ -1,5 +1,6 @@
 CONFIG_ZTEST=y
 CONFIG_DYNAMIC_INTERRUPTS=y
+CONFIG_ZTEST_NEW_API=y
 CONFIG_TEST_USERSPACE=y
 CONFIG_APPLICATION_DEFINED_SYSCALL=y
 CONFIG_MAIN_STACK_SIZE=1024
diff --git a/tests/arch/arm/arm_thread_swap/src/arm_syscalls.c b/tests/arch/arm/arm_thread_swap/src/arm_syscalls.c
index bb983c7..826cd01 100644
--- a/tests/arch/arm/arm_thread_swap/src/arm_syscalls.c
+++ b/tests/arch/arm/arm_thread_swap/src/arm_syscalls.c
@@ -150,7 +150,7 @@
 #endif
 }
 
-void test_arm_syscalls(void)
+ZTEST(arm_thread_swap, test_arm_syscalls)
 {
 	int i = 0;
 
@@ -163,7 +163,6 @@
 	 * - PSPLIM register guards the default stack
 	 * - MSPLIM register guards the interrupt stack
 	 */
-
 	zassert_true((_current->arch.mode & CONTROL_nPRIV_Msk) == 0,
 	"mode variable not set to PRIV mode for supervisor thread\n");
 
@@ -279,7 +278,7 @@
  *
  * @ingroup kernel_memprotect_tests
  */
-void test_syscall_cpu_scrubs_regs(void)
+ZTEST_USER(arm_thread_swap, test_syscall_cpu_scrubs_regs)
 {
 	uint32_t arm_reg_val[4];
 
@@ -297,12 +296,12 @@
 	}
 }
 #else
-void test_syscall_cpu_scrubs_regs(void)
+ZTEST_USER(arm_thread_swap, test_syscall_cpu_scrubs_regs)
 {
 	ztest_test_skip();
 }
 
-void test_arm_syscalls(void)
+ZTEST(arm_thread_swap, test_arm_syscalls)
 {
 	ztest_test_skip();
 }
diff --git a/tests/arch/arm/arm_thread_swap/src/arm_thread_arch.c b/tests/arch/arm/arm_thread_swap/src/arm_thread_arch.c
index a5cfc67..eab49fa 100644
--- a/tests/arch/arm/arm_thread_swap/src/arm_thread_arch.c
+++ b/tests/arch/arm/arm_thread_swap/src/arm_thread_arch.c
@@ -403,7 +403,7 @@
 		"Alternative thread: switch flag not false on thread exit\n");
 }
 
-void test_arm_thread_swap(void)
+ZTEST(arm_thread_swap, test_arm_thread_swap)
 {
 	int test_flag;
 
diff --git a/tests/arch/arm/arm_thread_swap/src/main.c b/tests/arch/arm/arm_thread_swap/src/main.c
index 862c552..b5b78ae 100644
--- a/tests/arch/arm/arm_thread_swap/src/main.c
+++ b/tests/arch/arm/arm_thread_swap/src/main.c
@@ -6,15 +6,4 @@
 
 #include <ztest.h>
 
-extern void test_arm_thread_swap(void);
-extern void test_arm_syscalls(void);
-extern void test_syscall_cpu_scrubs_regs(void);
-
-void test_main(void)
-{
-	ztest_test_suite(arm_thread_swap,
-		ztest_unit_test(test_arm_thread_swap),
-		ztest_unit_test(test_arm_syscalls),
-		ztest_user_unit_test(test_syscall_cpu_scrubs_regs));
-	ztest_run_test_suite(arm_thread_swap);
-}
+ZTEST_SUITE(arm_thread_swap, NULL, NULL, NULL, NULL, NULL);