watchdog: aspeed_wdt: Reorder output signal register configuration

If the output driving type is push-pull mode, the output
polarity should be selected in advance. Otherwise, an unexpected
value will be output at the moment of changing to push-pull mode.
Thus, output polarity, WDT18[31], must be configured before
changing driving type, WDT18[30].

Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Bonnie Lo <Bonnie_Lo@wiwynn.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220819094905.1962513-1-chin-ting_kuo@aspeedtech.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>