remove the broken SKMC driver

The SKMC driver has:
- already been marked as BROKEN in 2.6.0 three years ago and
- is still marked as BROKEN.

Drivers that had been marked as BROKEN for such a long time seem to be
unlikely to be revived in the forseeable future.

But if anyone wants to ever revive this driver, the code is still
present in the older kernel releases.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>