mtd: lpc32xx_slc: Remove unnecessary OOM messages

The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>