power: reset: adjust priority of simple syscon reboot driver

Currently, all restart handler use the priority 128, including
watchdogs. Probably most SoC have a watchdog, and some of them
register it also as a restart handler. But if a SoC specifies
a dedicated reboot capability using this syscon driver, this is
usually the preferred reboot method. Hence, raise the priority
of this driver to 192.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>