staging: vt6656: Remove unused driver

staging: vt6656: Remove unused driver

Forest Bond contributed this driver in 2009.

The following reasons lead to the removal:
- This driver generates maintenance workload
- This driver has a maximum 54MBit/s as it supports only 802.11 b/g.
  Peak throughput is 3MBytes/s.
- ping times can be 17ms are often above 500ms and worst case 22 seconds.
  One other user does not see such long ping times using a rasperry pi.

I suggest deleting the driver as it no longer meets current expectations
for throuput.

Link: https://lore.kernel.org/linux-staging/d18e714d-787f-4d30-a32f-4b0f55d2f5be@gmail.com/T/#t
Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/20241012164932.26390-1-philipp.g.hortmann@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>