Improved IRQ handling for e200 cores.
Improved IRQ handling for e200 cores.

git-svn-id: 5c281f329cfffd6b08c4f949a5c931454c7ea284@6567 35acf78f-673a-0410-8e92-d51de3d6d3f4

roboknight/chibios-lpc43xx,roboknight/chibios-lpc43xx