watchdog: sa11x0/pxa: fix error path of driver initialization

The change corrects release of captured resources on error path, namely
the clock is disabled and put if misc device registration fails and not
enabled clock is not disabled now.

Fixes: 6924089c ("watchdog: sa11x0/pxa: get rid of get_clock_tick_rate")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>