[KINETIS] Make TPM channels easier and more intuitive to use

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7500 35acf78f-673a-0410-8e92-d51de3d6d3f4
[KINETIS] Add PWM driver contributed by Adam Porter

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7501 35acf78f-673a-0410-8e92-d51de3d6d3f4