Add support for the Atollic Pro toolchain; Change extension .ihx to .hex to be...

Add support for the Atollic Pro toolchain; Change extension .ihx to .hex to be better compatible with most of the rest of the world

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4431 42af7a65-404d-4744-a932-0658087f49c3