wf111: new package

wf111: new package

Adds support for the BlueGiga WF111 WiFi driver and the binary utilities
distributed alongside the driver. An account is required to download the
sources from the BlueGiga website, which can be created freely. The
driver is available for armv5, arm7a and i386.

Since it is not possible to automatically retrieve the sources, because
of the required user account needed on the BlueGiga website, an option
is added to let the Buildroot user specify the directory where the
driver tarball was downloaded.

Finally, two options must be selected in the Linux kernel configuration:
CONFIG_WIRELESS_EXT and CONFIG_WEXT_PRIV. These are blind options (i.e.
not selectable directly) so they cannot be enabled by a change in
linux/linux.mk. The user as two choices to enable these options:
- By making them non blind, with a "WF111 support" configuration entry
  for example.
- By enabling another WiFi driver that select them.

The work behind this commit was funded by ECA Group
<http://www.ecagroup.com>. ECA Group is the copyright owner of the
contributed code.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>