DxeHttpIoLib: Http boot failure with no initializes timeout value.

https://bugzilla.tianocore.org/show_bug.cgi?id=3170
Using PcdHttpIoTimeout to set default timeout value to HttpIoLib.

Cc: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Signed-off-by: GregX Yeh <gregx.yeh@intel.com>
Reviewed-by: Siyuan Fu <siyuan.fu@intel.com>
Reviewed-by: Maciej Rabeda <maciej.rabeda@linux.intel.com>

NetworkPkg/Library/DxeHttpIoLib/DxeHttpIoLib.c

@@ -189,6 +189,7 @@ HttpIoCreateIo (
   HttpIo->Http        = Http;
   HttpIo->Callback    = Callback;
   HttpIo->Context     = Context;
+  HttpIo->Timeout     = PcdGet32 (PcdHttpIoTimeout);
 
   if (ConfigData != NULL) {
     if (HttpIo->IpVersion == IP_VERSION_4) {