Add -f option to filter in symbols from some libraries only

You can specify a regular expression for the -f option, typically
several library names combined with the '|' operator, as in:

bin/ios-mapfile-statistics -s -f 'libswlo|libsclo' <workdir/TiledLibreOffice.map|c++filt

Change-Id: I917fc392a41ed28c6b19ec5c2c16384d1186a532