jtag/hla: Restructure commands

jtag/hla: Restructure commands

Use a command group 'hla' with subcommands instead of individual
commands with 'hla_' prefix.

The old commands are still available to ensure backwards compatibility,
but are marked as deprecated.

Change-Id: I612e3cc080d308735932aea0f11001428eadc570
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: https://review.openocd.org/c/openocd/+/8335
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>