hla: use the new system_reset API

hla: use the new system_reset API

HLA uses its own internal driver's API to control the adapter's
system reset, but at the same time it calls jtag_add_reset() to
avoid breaking the internal logic of OpenOCD. This implicitly
forces HLA to rely on jtag queue mechanism, even if HLA has no
link with JTAG state machine. It requires HLA to implement an
empty execute_queue() to comply with the JTAG queue.

Modify the HLA framework and the HLA targets to use the new
adapter API for system_reset and decouple HLA from JTAG queue.
Rename the HLA static functions adapter_assert_reset() and
adapter_deassert_reset() to avoid overlap with the global
functions with same name.
While there, fix a minor typo in a comment s/incase/in case/.

Do not remove from HLA the JTAG specific API execute_queue(),
even if not required anymore, because OpenOCD code still has
calls to jtag_execute_queue() in case of non JTAG transport.

Change-Id: I0e65e3e557bd665bd3d3aeaa84ea609b55a05e48
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/4896
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>