SecurityPkg/Tcg2Dxe: Change comments of ShutdownTpmOnReset

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1460

Refer to Uefi spec 2.8, the ResetData is valid while ResetStatus
is EFI_SUCCESS regardless of the ResetType is EfiResetPlatformSpecific
or not.

Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
Reviewed-by: Chao Zhang <chao.b.zhang@intel.com>

SecurityPkg/Tcg/Tcg2Dxe/Tcg2Dxe.c

@@ -1,7 +1,7 @@
 /** @file
   This module implements Tcg2 Protocol.
 
-Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2015 - 2019, Intel Corporation. All rights reserved.<BR>
 (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -2419,10 +2419,7 @@ OnExitBootServicesFailed (
                                 EfiResetShutdown the data buffer starts with a Null-terminated
                                 string, optionally followed by additional binary data.
                                 The string is a description that the caller may use to further
-                                indicate the reason for the system reset. ResetData is only
-                                valid if ResetStatus is something other than EFI_SUCCESS
-                                unless the ResetType is EfiResetPlatformSpecific
-                                where a minimum amount of ResetData is always required.
+                                indicate the reason for the system reset.
                                 For a ResetType of EfiResetPlatformSpecific the data buffer
                                 also starts with a Null-terminated string that is followed
                                 by an EFI_GUID that describes the specific type of reset to perform.