QT4 mips: disable the LDFLAGS "-Bsymbolic-functions"
"-Bsymbolic-functions" flag makes ld to bind the global function symbol of shared library at compiling time, thus reduce the runtime relocation cost.
However, this flag in binutil 2.20 cause QT4 mips building failure, which is "final link failed: Bad value" error in libQtWebKit.so linking stage. If downgrad to binutil 2.19, this error disappears.
so before binutil new release is out, it is better to disable this flag for QT4 mips.
