For the few peripherals where it was being used (eg. uart, spi, etc) the output port
has been renamed to "int_o".

The only peripheral that was not touched is "wb_eic.vhd", because this one is being used
by wbgen, and it would require users to update their wbgen tool as well. So, until a new
tool is introduced, wbgen-generated interrupt controllers will have an output port called
wb_int_o".

Comparing std_logic <= '0' seems to work!
However, it is certainly not what the author intended.

wb_irq_slave: added clear and enable registers

	removed auto id from irqm_core
        TODO: fix auto IDs for wb_irq_master