sp-memusage: Fix QA issues

:Release Notes:
Correctly name meminfo library so it's picked by default FILES
variable, pass LDFLAGS so that they are respected. Include test
files sp-memusage-tests.

:Detailed Notes:
Fixes following QA warnings:
sp-memusage-1.3.2+gitAUTOINC+65e6a729ce04cd90206689ae28fbabc4baf801f6:
  sp-memusage: Files/directories were installed but not shipped
  /usr/lib/mallinfo.so
  /usr/share/sp-memusage-tests
  /usr/share/sp-memusage-tests/tests.xml
  /usr/share/sp-memusage-tests/test-mem-cpu-monitor.sh
sp-memusage-1.3.2+gitAUTOINC+65e6a729ce04cd90206689ae28fbabc4baf801f6:
  No GNU_HASH in the elf binary: 'sp-memusage/usr/bin/mem-monitor'
  No GNU_HASH in the elf binary: 'sp-memusage/usr/bin/mem-cpu-monitor'

:Testing Performed:
Only build tested.

:QA Notes:
No change to image.

:Issues Addressed:
[GF-42606] Ongoing metadata improvement/cleanup work
[GF-42650] Components not respecting LDFLAGS set in OE environment

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@lge.com>
Change-Id: Ifd9c57b53914ae35b529196c9dbf8b522660775c
Reviewed-on: https://g2g.palm.com/4011
Reviewed-by: DCO Verification
Build: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Tested-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>