Create the a new inout register to setup default value.
use it instead of GPIO register for O_E_N and TERM_E.

wrsw_dio/pulse_gen_pl: removed 1-subtraction from the pulse start time, which was calculated incorrectly for timestamps with cycles value == 0. Now the subtraction is done in the NIC driver

top level: shifted NIC and the rest of peripherals by 0x20000 to have enough address space to access SYSCON registers in the WRPC

wrsw_dio.vhd: fixed wrong address decoding (included most significant bits which should be masked out)