[KINETIS] Fixes to registers definitions

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7146 35acf78f-673a-0410-8e92-d51de3d6d3f4
[KINETIS] Initial K20 serial driver (Not working yet - WIP)

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7147 35acf78f-673a-0410-8e92-d51de3d6d3f4
[KINETIS] K20D50M board PB16/PB17 configured as USART0

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7148 35acf78f-673a-0410-8e92-d51de3d6d3f4