Documentation/networking: delete orphaned 3c505.txt file.

In the commit 0e245dba
("drivers/net: delete the 3Com 3c505/3c507 intel i825xx support")
we clobbered the 3c505 driver (over a year ago) along with other
abandoned ISA drivers.

However, this orphaned README file escaped detection at that
time, and has lived on until today. Get rid of it now.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/3c505.txt

-The 3Com Etherlink Plus (3c505) driver.
-
-This driver now uses DMA.  There is currently no support for PIO operation.
-The default DMA channel is 6; this is _not_ autoprobed, so you must
-make sure you configure it correctly.  If loading the driver as a
-module, you can do this with "modprobe 3c505 dma=n".  If the driver is
-linked statically into the kernel, you must either use an "ether="
-statement on the command line, or change the definition of ELP_DMA in 3c505.h.
-
-The driver will warn you if it has to fall back on the compiled in
-default DMA channel. 
-
-If no base address is given at boot time, the driver will autoprobe
-ports 0x300, 0x280 and 0x310 (in that order).  If no IRQ is given, the driver
-will try to probe for it.
-
-The driver can be used as a loadable module.
-
-Theoretically, one instance of the driver can now run multiple cards,
-in the standard way (when loading a module, say "modprobe 3c505
-io=0x300,0x340 irq=10,11 dma=6,7" or whatever).  I have not tested
-this, though.
-
-The driver may now support revision 2 hardware; the dependency on
-being able to read the host control register has been removed.  This
-is also untested, since I don't have a suitable card.
-
-Known problems:
- I still see "DMA upload timed out" messages from time to time.  These
-seem to be fairly non-fatal though.
- The card is old and slow.
-
-To do:
- Improve probe/setup code
- Test multicast and promiscuous operation
-
-Authors:
- The driver is mainly written by Craig Southeren, email
- <craigs@ineluki.apana.org.au>.
- Parts of the driver (adapting the driver to 1.1.4+ kernels,
- IRQ/address detection, some changes) and this README by
- Juha Laiho <jlaiho@ichaos.nullnet.fi>.
- DMA mode, more fixes, etc, by Philip Blundell <pjb27@cam.ac.uk>
- Multicard support, Software configurable DMA, etc., by
- Christopher Collins <ccollins@pcug.org.au>