meminfo/tools: Enable all libmeminfo based tools

Enables procrank, procmem, librank and showmap.
Only showmap gets built into the default builds.

Bug: 111694435
Test: builds
Test: showmap exists in final builds

Change-Id: Ib5901aa2bd4ccc6aa3d02915fda92f8320651315
Signed-off-by: Sandeep Patil <sspatil@google.com>