Input: s3c2410_ts - tone down logging

The S3C touchscreen driver is logging at LOG_INFO on every stylus up
event which spams the console needlessly.  Reduce the priority of the
message to debug level for some peace and quiet.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>