HEADS UP: XEN3.local instead of GENERIC.local

[Christoph Badura <bad%bsd.de@localhost>]

I've just change the i386 and amd64 XEN3* config files to include
XEN3.local instead of GENERIC.local.
This was in response to PR "port-xen/59438: GENERIC content can't be in
GENERIC.local because of XEN3_DOM* kernels"

While there I've also changed amd64/conf/XEN3_DOM0 to include
XEN3_DOM0.local if it exists for consistency with the other XEN3 config
files.

For the previous discussion see:
https://mail-index.netbsd.org/tech-kern/2024/08/11/msg029672.html

Those who have Xen-specific changes in GENERIC.local and don't want to
migrate them to XEN3.local should do the obvious thing:

    echo 'cinclude 	"arch/amd64/conf/GENERIC.local"' \
	>> sys/arch/amd64/conf/XEN3.local

Respectively:

    echo 'cinclude 	"arch/i386/conf/GENERIC.local"' \
	>> sys/arch/i386/conf/XEN3.local

--chris