target: Add support for ls1088a

target: Add support for ls1088a

The LS1088A is an octo-core aarch64 processor from NXP in the layerscape
family. The JTAG is undocumented, but I was able to figure things out
from the output of `dap info`. This is the first in-tree example of
using the hwthread rtos (as far as I know), so hopefully it can serve as
an example to other developers. There are some ETMs, but I was unable to
try them out because I got 'invalid command name "etm"' when trying to
test things out.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Change-Id: I9b0791d27d8c41170a413a8d86431107a85feba2
Reviewed-on: https://review.openocd.org/c/openocd/+/6848
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>