In its current form, dcr_map() doesn't remember the base address you passed
it, which means you need to store it somewhere else.  Rather than adding the
base to another struct it seems simpler to store it in the dcr_host_t.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>