Add wrappers to functions used by the Monitor

Add wrappers to functions used by the Monitor

Some functions exported to be used by the Monitor as command
handlers are also called in other places as regular functions.

When those functions got ported to use the Monitor dictionary
to pass argments, the callers will have to setup a dictionary
to be able to call them.

To avoid this problem, this commit add wrappers to those functions,
so that we change the wrapper to accept the dictionary, letting
the current functions as is.

The following wrappers are being added:

- do_help_cmd()
- do_pci_device_hot_remove()

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>