xc2bit: Fix bug with 32A ZIA encoding
xc2bit: Fix bug with 32A ZIA encoding

The much earlier fix for the larger macrocell devices was causing the
32-macrocell ZIA bits to get mirrored. Also, for the sake of
consistency, replace the 32-macrocell ZIA encode/decode with a pattern
match rather than explicitly setting mux bits

azonenberg/openfpga,azonenberg/openfpga,rqou/openfpga,rqou/openfpga,rqou/openfpga,azonenberg/openfpga,rqou/openfpga,azonenberg/openfpga,azonenberg/openfpga,rqou/openfpga