bugfix, dp_switch now realy switching

libraries/base/diag/src/vhdl/diag_data_buffer_dev.vhd

libraries/base/dp/src/vhdl/dp_mux.vhd

libraries/base/dp/src/vhdl/dp_switch.vhd

libraries/base/dp/tb/vhdl/tb_dp_switch.vhd