s390-tools: Introduce new tool zmemtopo

s390 is able to provide memory topology information of the current CEC
via a new userspace-kernel interface. zmemtopo is a tool to convert the
raw data into human readable form.

Usage: zmemtopo [OPTIONS]

Display CEC memory topology of allocated memory increments.

OUTPUT FORMAT OPTIONS
 -l, --level NESTING_LEVEL  Set the topology display depth to NESTING_LEVEL
 -f, --full                 Display tree view with padded elements
 -r, --reverse              Reverse tree view hierarchy direction
 -t, --table                Use table view to display topology
 -s, --sort FIELD           Sort view by field
                            (nr, lpar, size)
 -i, --ascii                Use only ASCII characters

GENERAL OPTIONS
 -h, --help                 Print this help, then exit
 -v, --version              Print version information, then exit

Upon calling zmemtopo displays available topology level's structure
and memory increments defined on each topology location.

Ex:
$ zmemtopo
LPAR/LEVEL     SIZE
LPAR003          8G
└LEVEL4_0        8G
  ├LEVEL3_0      2G
  ├LEVEL3_1      2G
  ├LEVEL3_2      2G
  └LEVEL3_3      2G
LPAR005          8G
└LEVEL4_1        8G
  ├LEVEL3_0      2G
  ├LEVEL3_1      2G
  ├LEVEL3_2      2G
  └LEVEL3_3      2G
LPAR006          8G
└LEVEL4_3        8G
...

Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

Makefile

@@ -16,7 +16,7 @@ TOOL_DIRS = zipl zdump fdasd dasdfmt dasdview tunedasd \
 	   ziomon iucvterm hyptop cmsfs-fuse qethqoat zfcpdump zdsfs cpumf \
 	   systemd hmcdrvfs cpacfstats zdev dump2tar zkey netboot etc zpcictl \
 	   lsstp hsci hsavmcore chreipl-fcp-mpath ap_tools rust opticsmon \
-	   zpwr
+	   zpwr zmemtopo
 
 else
 BASELIB_DIRS =