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: 91694e1d9b5d22056427bd887886ba5d7b9f66f7
  1. cells/
  2. models/
  3. tech/
  4. LICENSE
  5. README.rst