[PR] Change PR to FILE_PR and intro PR as FILE_PR + DISTRO_PR

[PR] Change PR to FILE_PR and intro PR as FILE_PR + DISTRO_PR
    Allow a distribution to globally bump the PR of every package
    this is useful when there was a change in the toolchain and
    every package is going to be different.

    find packages/ \( -name '*.bb' -or -name '*.inc' \) -exec sed -i s/"^PR="/"FILE_PR ="/ {} \;
    find packages/ \( -name '*.bb' -or -name '*.inc' \) -exec sed -i s/"^PR ="/"FILE_PR ="/ {} \;

Acked-By: Koen Kooi <koen@openembedded.org>