drivers: xds110: Add support TCK changes in firmware update

drivers: xds110: Add support TCK changes in firmware update

Starting with XDS110 firmware version 3.0.0.0, the peak TCK
frequency became 14,000 kHz. So the delay count calculation
in the current driver has been updated to use the new
formula for setting the TCK speed depending on which version
of the firmware is detected. And because of the changes, the
default TCK settings for the XDS110 based Launchpads can be
adjusted to take advantage of the higher TCK performance.
Note that the values used have been determined through
testing in the automated test labs to be the highest TCK
frequency with the XDS110 that are still reliable.
Different boards have a different peak TCK setting that
should be safe.

Change-Id: I4d66e90d8fac8272641ba4db4a3a510e3b444d86
Signed-off-by: Edward Fewell <efewell@ti.com>
Reviewed-on: http://openocd.zylin.com/5493
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>