- Add new jtag_config_khz to increase encapsulation of jtag->khz call.
- Add new jtag_get_speed_readable to encapsulate of jtag->speed_div call.
- Make definition of jtag static in core.c, remove extern from tcl.c.


git-svn-id: svn://svn.berlios.de/openocd/trunk@2171 b42882b7-edfa-0310-969c-e2dbd0fdcd60