Cups filters are no longer built by default. Since ghostscript already depends
on cups, build the filters and package them as ghostscript-cups.
Ghostscript uses the cups-config script from the oe sysroots to determine some
of the target install paths, as well as to determine the linker path. The config
script gives out paths pointing to the sysroot, so some of the paths needed to
be adjusted in the Makefile.
Signed-off-by: James Limbouris <james@digitalmatter.com.au>
