testing/pm_smp: add more delay, avoid idle canot run one cycle

If the host performance low, possible not able to enter idle thread,
cause case break.

Signed-off-by: buxiasen <buxiasen@xiaomi.com>

Author: jasonbu

testing/drivers/drivertest/drivertest_pm_smp.c

@@ -46,9 +46,9 @@
 
 #define TEST_PM_LOOP_COUNT   5
 
-#define TEST_STAYTIMEOUT     2   /* in ms */
+#define TEST_STAYTIMEOUT     20   /* in ms */
 
-#define TEST_SNAP_TICK_MAX   3
+#define TEST_SNAP_TICK_MAX   5
 
 #define TEST_TIMEOUT_ENABLED 1