git ssb

Makefile: fix parallel build

version.h is included by some .o files, but it is generated. As such, it
must be a dependency of those .o files.

Rather than filter exactly which .o file needs it, just add a generic
dependency for all .o files on version.h.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>