rtc: abx80x: use devm_add_action_or_reset()

If devm_add_action() fails we are explicitly calling the cleanup to free
the resources allocated.  Lets use the helper devm_add_action_or_reset()
and return directly in case of error, as we know that the cleanup function
has been already called by the helper if there was any error.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>