[PATCH] pc8736x_gpio: fix re-modprobe errors: fix/finish cdev-init

- Switch from register_chrdev() to   (register|alloc)_chrdev_region().

- use a cdev.  This was intended for original patchset, but was
  overlooked.

  We use a single cdev for all pins (minor device-numbers), as gleaned
  from cs5535_gpio, and in contrast to whats currently done in scx200_gpio
  (which I'll fix soon)

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>