SimicsOpenBoardPkg: Update Vtf0 binary rule in Fdf

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2307



Updated the RESET_VECTOR rule since ResetVector/Vtf0
is now built from source.

Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Michael Kubacki <michael.a.kubacki@intel.com>
Signed-off-by: Prince Agyeman <prince.agyeman@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Michael Kubacki <michael.a.kubacki@intel.com>