fixdep: remove unneeded code and comments about *.ver files

This is probably stale code. In old days (~ Linux 2.5.59), Kbuild made
genksyms generate include/linux/modules/*.ver files.

The currenct Kbuild does not generate *.ver files at all.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>