The ADC DMA will never underflow and unsurprisingly the adc_dunf signal is
never used anywhere. It is very unlikely it will ever be used, so remove
it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The DC filter implementation in library/common/dc_filter.v is Xilinx
specific as it uses the Xilinx DSP48 hard-macro. There is a matching Altera
specific implementation in library/altera/common/dc_filter.v.
Move the Xilinx specific implementation from the generic common folder to
the Xilinx specific common folder in library/xilinx/common/ since that is
where all other Xilinx specific common modules reside.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>