Add RoboSwitch driver interface for wpa_supplicant

Add RoboSwitch driver interface for wpa_supplicant

Find attached the patch that creates a new driver: roboswitch. This
driver adds support for wired authentication with a Broadcom
RoboSwitch chipset. For example it is now possible to do wired
authentication with a Linksys WRT54G router running OpenWRT.

LIMITATIONS
- At the moment the driver does not support the BCM5365 series (though
adding it requires just some register tweaks).
- The driver is also limited to Linux (this is a far more technical
restriction).
- In order to compile against a 2.4 series you need to edit
include/linux/mii.h and change all references to "u16" in "__u16". I
have submitted a patch upstream that will fix this in a future version
of the 2.4 kernel. [These modifications (and more) are now included in
the kernel source and can be found in versions 2.4.37-rc2 and up.]

USAGE
- Usage is similar to the wired driver. Choose the interfacename of
the vlan that contains your desired authentication port on the router.
This name must be formatted as <interface>.<vlan>, which is the
default on all systems I know.