watchdog: cadence: Do not show error in case of deferred probe

There is no reason to show error message if clocks are not ready yet.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/d3e295d5ba79f453b4aa4128c4fa63fbd6c16920.1570544944.git.michal.simek@xilinx.com


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