tools/libxc: Modify bitmap operations to take void pointers

tools/libxc: Modify bitmap operations to take void pointers

The type of the pointer to a bitmap is not interesting; it does not affect the
representation of the block of bits being pointed to.

Make the libxc functions consistent with those in Xen, so they can work just
as well with 'unsigned int *' based bitmaps.

As part of doing so, change the implementation to be in terms of char rather
than unsigned long.  This fixes alignment concerns with ARM.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>