extcon: Remove unnecessary OOM messages

The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message. The following
checkpatch warning is also removed.

  WARNING: Possible unnecessary 'out of memory' message

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
[Acked by Charles Keepax for arizona part]
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>