Fix Greentea test common_tickers failed

1. Disable ticker interrupt which would interfere with fire_interrupt speed test
2. Enlarge test period to avoid timeout error

Author: ccli8

TESTS/mbed_hal/common_tickers/main.cpp

@@ -473,11 +473,14 @@ void ticker_speed_test(void)
 
     /* ---- Test fire_interrupt function. ---- */
     counter = NUM_OF_CALLS;
+    /* Disable ticker interrupt which would interfere with speed test */
+    core_util_critical_section_enter();
     start = us_ticker_read();
     while (counter--) {
         intf->fire_interrupt();
     }
     stop = us_ticker_read();
+    core_util_critical_section_exit();
 
     TEST_ASSERT(diff_us(start, stop, us_ticker_info) < (NUM_OF_CALLS * (MAX_FUNC_EXEC_TIME_US + DELTA_FUNC_EXEC_TIME_US)));
 
@@ -569,7 +572,7 @@ utest::v1::status_t lp_ticker_teardown(const Case *const source, const size_t pa
 
 utest::v1::status_t test_setup(const size_t number_of_cases)
 {
-    GREENTEA_SETUP(30, "default_auto");
+    GREENTEA_SETUP(80, "default_auto");
     return verbose_test_setup_handler(number_of_cases);
 }