watchdog: sp5100_tco: Use dev_ print functions where possible

Use dev_ instead of pr_ functions where possible.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>