Merge old and new project constraints
Update top/fe-link-histogram/firmware/ucf/emp_project_constraints_old.tcl, top/fe-link-histogram/firmware/ucf/emp_project_constraints.tcl files
Update top/fe-link-histogram/firmware/ucf/emp_project_constraints_old.tcl, top/fe-link-histogram/firmware/ucf/emp_project_constraints.tcl files