drivers/pcmcia/pd6729.c: convert to module_pci_driver

Use module_pci_driver instead of init/exit, make code clean.

Signed-off-by: Libo Chen <libo.chen@huawei.com>
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>