pcmcia: add locking to set_mem_map()

Protect the pccard_operations callback "set_mem_map" by a new
mutex ops_mutex. This mutex also protects the following values
in struct pcmcia_socket:

        pccard_mem_map          win[]
        pccard_mem_map          cis_mem
        void __iomem            *cis_virt

Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

drivers/pcmcia/cs.c

@@ -222,6 +222,7 @@ int pcmcia_register_socket(struct pcmcia_socket *socket)
 	init_completion(&socket->socket_released);
 	init_completion(&socket->thread_done);
 	mutex_init(&socket->skt_mutex);
+	mutex_init(&socket->ops_mutex);
 	spin_lock_init(&socket->thread_lock);
 
 	if (socket->resource_ops->init) {