Fix the name of nwell and rdl generic resistors.

Convert `mrnw` to `sky130_fd_pr__res_generic_nw`.
Convert `mrrdl` to `sky130_fd_pr__res_generic_r1`.

Fixes https://github.com/google/skywater-pdk/issues/168

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>
tree: 6613a9a19fc9293ca49805ad232e6b882f5bf523
  1. LICENSE
  2. README.rst
  3. cells/
  4. models/