hw/scripts: Allow GDB script for MTB to be used on crash dumps
hw/scripts: Allow GDB script for MTB to be used on crash dumps

If 'mtb_state_at_crash' symbol is present in core dump MTB script
can be used on crash dump files to see what lead to crash.

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core