[S390] zfcpdump: Make SCSI disk dump tool recognize storage holes

The kernel part of zfcpdump establishes a new debugfs file zcore/memmap
which exports information on memory layout (start address and length of each
memory chunk) to its userspace counterpart.

Signed-off-by: Frank Munzert <munzert@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>