Move timeMode property to manager

The current logic is to maintain the same attribute in manager and
epoch_base, the purpose of this commit is to merge this attribute
into manager for maintenance.

Also, Update the test/TestBmcEpoch.cpp file.

Tested: Built phosphor-time-manager successfully and UT passed.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I05fea271d672bf12ecb722005023dfa6a2a980d1
diff --git a/bmc_epoch.hpp b/bmc_epoch.hpp
index d8abe2f..10dbf7b 100644
--- a/bmc_epoch.hpp
+++ b/bmc_epoch.hpp
@@ -19,8 +19,7 @@
 class BmcEpoch : public EpochBase
 {
   public:
-    friend class TestBmcEpoch;
-    BmcEpoch(sdbusplus::bus_t& bus, const char* objPath);
+    BmcEpoch(sdbusplus::bus_t& bus, const char* objPath, Manager& manager);
     ~BmcEpoch();
 
     /**