SimicsOpenBoardPkg: Update usage of functions to be removed

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2777


With some functions to be deprecated, their usage in platforms
should also be updated.

Cc: Agyeman Prince <prince.agyeman@intel.com>
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Prince Agyeman <prince.agyeman@intel.com>