[Gdb] Enable HW breakpoint for ARM

[Ruedi Dummermuth]

Hi all,

Is it possible to build a cross GDB for ARM (arm-elf) so it enables
the use of the "hbreak" command and sends the appropriate
Z-packet to the target. I ask this because I have a GDB stub
(actually a JTAG debug interface) that can support hardware
breakpoints and watchpoints.

Currently I get always the message:
"No hardware breakpoint support in the target"

Thanks,
Ruedi