Renamed system directory to nanosoc

...nosoc_subsystems/expansion/verilog/nanosoc_ss_expansion.v

...subsystems/interconnect/verilog/nanosoc_ss_interconnect.v

...soc_subsystems/systemctrl/verilog/nanosoc_ss_systemctrl.v

nanosoc/nanosoc_system/verilog/nanosoc_system.v

system/slcorem0_tech

system/sldma230_tech

system/socdebug_tech