Multiple fixes for simulation

hdl/corr_pi.vhd

hdl/data_serializer.vhd

hdl/matrix_mul.vhd

hdl/orbit_error.vhd

hdl/pkg_corrmatrixpi.vhd

hdl/top_corr_matrixpi.vhd

rdl/corr_matrixpi.rdl

sim/tb_corr_matrixpi.vhd

sim/tc_basic.vhd

sim/view1.gtkw