mfd: pcf50633: Fix some memory leaks in the error handling path of 'pcf50633_probe()'

If a 'platform_device_alloc()' call fails, we still need to release the
resources that have already been allocated before returning.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Lee Jones <lee.jones@linaro.org>