[WATCHDOG] Winbond SMsC37B787 watchdog fixes

* Added io spinlocking
* Deleted WATCHDOG_MINOR (it's in the miscdevice include
* Changed timer_enabled to use set_bit functions
* WDIOC_GETSUPPORT should return -EFAULT or 0
* timeout should be correct before we initialize the watchdog
* we should initialize the watchdog before we give access
  to userspace
* Third parameter of module_param is not the default or
  initial value

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>