mfd: pcf50633: Reconnect -ENOMEM error path

If platform_device_alloc() or platform_device_add_data() fail during
pcf50633_probe(), the current code ignores the return error code and
continues to attempt to allocate new platform devices for each of the
supported regulators.  Instead, if any failures occur we should fail
out gracefully by cleaning up after ourselves and return the error.

Signed-off-by: Lee Jones <lee.jones@linaro.org>