MdeModulePkg/SetupBrowserDxe: Get default from callback for orderedList

MdeModulePkg/SetupBrowserDxe: Get default from callback for orderedList

For orderedlist question, the value is stored in a buffer,
not in HiiValue. So when need to get default value from callback
function for orderedlist, need to pass the buffer.
This patch is to enhance this logic.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>