x86/platform/intel-mid: Move watchdog registration to arch_initcall()

There is no need to choose a random initcall level for certainly
architecture dependent code.

Move watchdog registration to arch_initcall() from rootfs_initcall().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: http://lkml.kernel.org/r/20170119192425.189899-5-andriy.shevchenko@linux.intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>