Add code to assert() if non ISR safe API function is called from ISR in Tasking CM4F ports - plus fix bug where the max syscall interrupt priority was used incorrectly in the Tasking CM4F port.

git-svn-id: http://svn.code.sf.net/p/freertos/code/trunk@2262 1d2547de-c912-0410-9cb9-b8ca96c0e9e2