SecurityPkg: SecureBootConfigDxe: Support AUTH_2 enrollment to DBX

Update SecureBootConfigDxe to support AUTH_2 format data enrollment
to DBX.
Free opened file handle resource after exit PK/KEK/DB/DBX/DBT
enrollment page.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chao Zhang <chao.b.zhang@intel.com>
Reviewed-by: Long Qin <qin.long@intel.com>

SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigImpl.h

@@ -47,6 +47,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Guid/FileSystemVolumeLabelInfo.h>
 #include <Guid/ImageAuthentication.h>
 #include <Guid/FileInfo.h>
+#include <Guid/WinCertificate.h>
 
 #include "SecureBootConfigNvData.h"
 
@@ -108,6 +109,7 @@ typedef struct {
 typedef struct {
   EFI_FILE_HANDLE                   FHandle;
   UINT16                            *FileName;
+  UINT8                             FileType;
 } SECUREBOOT_FILE_CONTEXT;