Remove Deferred Updates

Remove deferred consumption of settings Manual/NTP and allow instant
consumption.

Tested:
Manually set the timeMode to NTP on the WEB and successfully.
busctl get-property xyz.openbmc_project.Settings
/xyz/openbmc_project/time/sync_method
xyz.openbmc_project.Time.Synchronization TimeSyncMethod
s "xyz.openbmc_project.Time.Synchronization.Method.NTP"

Manually set the date time successfully by D-Bus when timeMode is MANUAL
busctl set-property xyz.openbmc_project.Time.Manager
/xyz/openbmc_project/time/bmc xyz.openbmc_project.Time.EpochTime Elapsed
t 1514765953791262

Manually set the date time failed by D-Bus when timeMode is NTP.
busctl set-property xyz.openbmc_project.Time.Manager
/xyz/openbmc_project/time/bmc xyz.openbmc_project.Time.EpochTime Elapsed
t 1514765953791262
Failed to set property Elapsed on interface
xyz.openbmc_project.TIme.EpochTime: The operation failed

~# journalctl -b | grep timemanager
   Jan 01 00:15:26 fp5280g2 phosphor-timemanager[309]: Error in setting
system time
   Jan 01 00:15:26 fp5280g2 phosphor-timemanager[309]: The operation
failed

Refer: https://lists.ozlabs.org/pipermail/openbmc/2020-April/021409.html

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I7be25a9d0f56615bad6800a0b07df7f84fc0acc3
diff --git a/test/TestBmcEpoch.cpp b/test/TestBmcEpoch.cpp
index db43854..5ed1f3c 100644
--- a/test/TestBmcEpoch.cpp
+++ b/test/TestBmcEpoch.cpp
@@ -51,6 +51,15 @@
     }
 };
 
+TEST_F(TestBmcEpoch, onModeChange)
+{
+    bmcEpoch->onModeChanged(Mode::NTP);
+    EXPECT_EQ(Mode::NTP, getTimeMode());
+
+    bmcEpoch->onModeChanged(Mode::Manual);
+    EXPECT_EQ(Mode::Manual, getTimeMode());
+}
+
 TEST_F(TestBmcEpoch, empty)
 {
     // Default mode is MANUAL