NetworkPkg: Handling timeout case in httpboot driver

This patch is used to handle timeout case when downloading
the message. The Status in the token should also be checked
to handle any response error case including timeout case.

Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Ye Ting <ting.ye@intel.com>
Cc: Zhang Lubo <lubo.zhang@intel.com>
Cc: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>
Cc: Gary Lin <glin@suse.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Gary Lin <glin@suse.com>
Reviewed-by: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>
Tested-by: Gary Lin <glin@suse.com>
Tested-by: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>

NetworkPkg/HttpBootDxe/HttpBootSupport.h

@@ -196,6 +196,8 @@ typedef struct {
 
   BOOLEAN                   IsTxDone;
   BOOLEAN                   IsRxDone;
+
+  EFI_EVENT                 TimeoutEvent;
 } HTTP_IO;
 
 //