ztest: Make cpu hold time configurable

3000 milliseconds may not always be enough time for all 1cpu type
tests to finish on all platforms. Making the CPU hold time
configurable allows for additional flexibility.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>

subsys/testsuite/ztest/Kconfig

@@ -29,6 +29,17 @@ config ZTEST_TEST_DELAY_MS
 	  Add a delay between between tests to manage output on the console on
 	  systems that can't handle the rapid output rate.
 
+config ZTEST_CPU_HOLD_TIME_MS
+	int "Time in milliseconds to hold other CPUs for 1cpu type tests"
+	default 3000
+	help
+	  This option is used to specify the maximum time in milliseconds for
+	  which a 1cpu type test may execute on a multicpu system. The default
+	  value ought to suffice for most such tests; however slower platforms
+	  (which may include simulators) may need to set this to a larger
+	  value. Please be aware that increasing it for long-running test cases
+	  may overload the CI system. Modify with caution.
+
 config ZTEST_FAIL_FAST
 	bool "Abort on first failing test"
 	help

subsys/testsuite/ztest/src/ztest.c

@@ -131,7 +131,7 @@ static void cpu_hold(void *arg1, void *arg2, void *arg3)
 	 * logic views it as one "job") and cause other test failures.
 	 */
 	dt = k_uptime_get_32() - start_ms;
-	zassert_true(dt < 3000,
+	zassert_true(dt < CONFIG_ZTEST_CPU_HOLD_TIME_MS,
 		     "1cpu test took too long (%d ms)", dt);
 	arch_irq_unlock(key);
 }

subsys/testsuite/ztest/src/ztest_new.c

@@ -152,7 +152,8 @@ static void cpu_hold(void *arg1, void *arg2, void *arg3)
 	 * logic views it as one "job") and cause other test failures.
 	 */
 	dt = k_uptime_get_32() - start_ms;
-	zassert_true(dt < 3000, "1cpu test took too long (%d ms)", dt);
+	zassert_true(dt < CONFIG_ZTEST_CPU_HOLD_TIME_MS,
+		     "1cpu test took too long (%d ms)", dt);
 	arch_irq_unlock(key);
 }