Add mkimg_chs() for those schemes that need the LBA broken down into
cylinder, head and track numbers. Return ~0U for these values when
mkimg wasn't given both -T and -H (i.e. no geometry) or the cylinder
would be larger than the provided maximum.

Use mkimgs_chs() for the EBR, MBR and PC98 schemes to fill in the
appropriate fields. Make sure to use a "rounded" size so that the
partition is always a multiple of the track size. We reserved the
room for it in the metadata callback so that's a valid thing to
do.

Bump the mkimg version number.
While doing that again: have mkimg.o depend on the Makefile so that
a version change triggers a rebuild as needed.
Update baseline files for EBR, MBR and PC98 now that mkimg fills in
the CHS fields appropriately when -T and -H are given on the command
line.