Staging: add et131x network driver

This is a driver for the ET1310 network device.

Based on the driver found at https://sourceforge.net/projects/et131x/

Cleaned up immensely by Olaf Hartman <o.hartmann@telovital.com> and Christoph
Hellwig <hch@infradead.org>

Note, the powermanagement options were removed from the vendor provided
driver as they did not build properly at the time.

TODO:
	- kernel coding style cleanups
	- forward port for latest network driver changes
	- kill useless typecasts (e.g. in et1310_phy.c)
	- alloc_etherdev is initializing memory with zero?!?
	- add_timer call in et131x_netdev.c is correct?
	- Add power saving functionality (suspend, sleep, resume)
	- Implement a few more kernel Parameter (set mac )

Cc: Olaf Hartmann <o.hartmann@telovital.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dean Adams <dadams1969@gmail.com>
Cc: Victor Soriano <vjsoriano@agere.com>
Cc: Andre-Sebastian Liebe <andre@lianse.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>