thermal: rcar: 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: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>