bitops: Change the bitmap index from int to unsigned long [mn10300]

Change the index to unsigned long in all bitops for [mn10300]

Signed-off-by: Justin Chen <justin.chen@hp.com>
Reviewed-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: David Howells <dhowells@redhat.com>