Alexei Babich <a.babich@rez.ru> fix problems with unecessary tailend byte...

Alexei Babich <a.babich@rez.ru> fix problems with unecessary tailend byte accesses. Use 16 bit access on tailend of a memory read if possible.

git-svn-id: svn://svn.berlios.de/openocd/trunk@2684 b42882b7-edfa-0310-969c-e2dbd0fdcd60