Fix weston fails to start when mapview-demo enabled

Fix weston fails to start when mapview-demo enabled

Some part of weston which support mapview-demo refers library in
/usr/local/lib.

To solve this, make symblic link directory into /usr/lib because
adding /usr/local/lib into library search path in anyway didn't
work well.

  E.g. Environment=LD_LIBRARY_PATH=/usr/local/lib in weston service
  E.g. LD_LIBRARY_PATH=/usr/local/lib in /etc/environment
  E.g. Adding /usr/local/lib into /etc/ld.so.conf

Change-Id: I9d85732c18d1c9b13343304f45b53cfc806ec941
Signed-off-by: Tadao Tanikawa <tanikawa.tadao@jp.panasonic.com>