Merge branch 'w5100-spi-and-w5200-support'

Akinobu Mita says:

====================
net: w5100: add support W5100/W5200 for SPI interface

This series add support for Wiznet W5100 and W5200 for SPI interface.

We can easily find the ethernet modules and shield for Arduino with
these chips for purchase.  I've tested them with BeagleBone.

Wiznet W5100 for mmio access has already supported by w5100 driver.

In order to share the code between mmio mode and SPI mode, this series
firstly adds ability to support another register access interface to
the existing w5100 driver.  This ground work also requires to introduce
workqueue and threaded irq because SPI transfers are callable only from
contexts that can sleep unlike mmio access.

The latter part of this series adds w5100-spi driver which actually
support W5100 and W5200 for SPI interface.  Supporting W5100 is
straight forward because it only required to add a register access
interface by the SPI transfer.  W5100 and W5200 have similar memory
map which justifies adding W5200 support to w5100 driver.

* Changes from v2 to v3
- Add comment for reg_lock
- Add ability to allocate ops specific data structure
- Allocate w5200 ops specific data structure to put DMA-safe buffer
- Add missing chip_id assignment for w5100_*_ops

* Changes from v1 to v2
- Use a plain single pointer instead of SKB queue, spotted by David S. Miller
- Correct timeout period in w5100_command
- Use spi_write_then_read instead of spi_write which needs DMA-safe buffer
- Support W5200
====================

Signed-off-by: David S. Miller <davem@davemloft.net>