arch/arc: Set the right priority for WDT on quark_se

ARC has only 2 priorities, 0 or 1. So let's set the right priority for
WDT.

It looks like some commit has changed that, somewhere. And wrong
priorities were lurking around.

Fixes #8096

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>