sparc64: Support reserving memory with memmap=xxx$yyy

sparc64: Support reserving memory with memmap=xxx$yyy

The kernel commandline parameter memmap= was supported
on several other architectures but not on SPARC (it was
being ignored on SPARC).

Add support for the memmap=xxx$yyy commandline parameter
(sparc64/UEK4 only). The patch is based on the existing
code for the "tile" architecture.

There are other types of memmap= commandlines which
are only supported on x86 that are e820-specific.
These were not implemented.

Orabug: 22662762

Signed-off-by: Larry Bassel <larry.bassel@oracle.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>