eglibc.inc: Transfer PARALLEL_MAKE to PARALLELMFLAGS
* Currently we are passing -jN or -j N flags to eglibc makefiles
however eglibc uses a make variable called PARALLELMFLAGS
to pass information about parallel build to sub-makes
* Currently make install ran without parallelism but now
it should have parallel building flags passed to do_install
correctly which inturn should improve build time of
eglibc on systems using parallel build -j with values > 1
