openocd: properly use jim data types

openocd: properly use jim data types

The jim library exports all the data types through typedef, so
there is no need to use the internal struct types.

Fix the few remaining inconsistencies in the code.

Change-Id: Id4ae0083563ea7a371833374e7b39f17158f66a4
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5662
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Tested-by: jenkins