spi: sun4i: Driver cleanup

- drop unused macros.
- use base instead of base_addr, for better code readability
- move .probe and .ofdata_to_platdata functions in required
  places to add platdata support in future.
- use sentinel sun4i_spi_ids.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
1 file changed