tokenring: delete all remaining driver support

This represents the mass deletion of the of the tokenring support.

It gets rid of:
  - the net/tr.c which the drivers depended on
  - the drivers/net component
  - the Kbuild infrastructure around it
  - any tokenring related CONFIG_ settings in any defconfigs
  - the tokenring headers in the include/linux dir
  - the firmware associated with the tokenring drivers.
  - any associated token ring documentation.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

drivers/net/Kconfig

@@ -282,8 +282,6 @@ source "drivers/net/slip/Kconfig"
 
 source "drivers/s390/net/Kconfig"
 
-source "drivers/net/tokenring/Kconfig"
-
 source "drivers/net/usb/Kconfig"
 
 source "drivers/net/wireless/Kconfig"