staging/sb105x: remove asm/segment.h dependency

sb105x doesn't seem to actually need <asm/segment.h> (builds on x86
without it) and ppc/ppc64 doesn't provide it so it fails to build there.

This patch removes the dependency.

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