fix(addr): reduce hierarchy; fix INTERCONNECT addresses

There surely was a reason to define a separate addrmap for each instantiated addrmap in SystemRDL files generated by genRdlFromParent. It might not be needed anymore and just cause confusion and clutter.

The INTERCONNECT type of address space node should now work as expected. For example, a module with a block design "bd_app" and several internal or external subordinates might best be described like this:

addAddressSpace AddressSpace "bd_app" INTERCONNECT {} {}
addAddressSpace AddressSpace "bd_ip_1" IPX {0x00200000} bd_ip_1
addAddressSpace AddressSpace "test_regs" RDL {0x00210000} ../rdl/test_regs.rdl

Even if this module is instantiated at an offset, e.g. 0x44000000, the generated RDL file should internally instantiate "bd_ip_1" and "test_regs" at their relative addresses.