Broken makefile dependency between `install` and `.pc` targets

[silentbicycle]

This may be a kmkf issue.

bmake -r install fails if the ${BUILD}/pc/{libfsm,libre}.pc files are missing. Running bmake -r build/pc/libfsm.pc and bmake -r build/pc/libre.pc and then bmake -r install works, but the install target should depend on them.