staging: sb105x: delete the driver

It's been marked BROKEN for over a year, and no one has stepped up to do
anything with the code, and no one has complained.  So just delete it.
If someone wants to fix it up and merge it "properly", they can revert
this commit.

Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>