Add support for generating a systemtap tapset static probes

Add support for generating a systemtap tapset static probes

This introduces generation of a qemu.stp/qemu-system-XXX.stp
files which provides tapsets with friendly names for static
probes & their arguments. Instead of

    probe process("qemu").mark("qemu_malloc") {
        printf("Malloc %d %p\n", $arg1, $arg2);
    }

It is now possible todo

    probe qemu.system.i386.qemu_malloc {
        printf("Malloc %d %p\n", size, ptr);
    }

There is one tapset defined per target arch.

* Makefile: Generate a qemu.stp file for systemtap
* tracetool: Support for generating systemtap tapsets

Signed-off-by: Daniel P. Berrange <[email protected]>
Signed-off-by: Anthony Liguori <[email protected]>