pcmcia: switch cm4000_cs.c to unlocked_ioctl

Push the BKL down and use unlocked_ioctl.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Harald Welte <laforge@gnumonks.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>