I2C. Alberto's clock setting code tested. Minor changes.
I2C. Alberto's clock setting code tested. Minor changes.

git-svn-id: 42fb8b5ac3c3e37b202b6eb62b1b650836efe64b@2721 35acf78f-673a-0410-8e92-d51de3d6d3f4

roboknight/chibios-lpc43xx,roboknight/chibios-lpc43xx