Reverted addition of make rules for creating dummy dependency files.

It's now done by configure.

Rev: src/nettle/ChangeLog:1.298
Rev: src/nettle/Makefile.in:1.10
Rev: src/nettle/examples/Makefile.in:1.7
Rev: src/nettle/testsuite/Makefile.in:1.7
Rev: src/nettle/tools/Makefile.in:1.8