bin/60747: wsconsctl could be smarter about not showing edid

["uwe%stderr.spb.ru@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60747
>Category:       bin
>Synopsis:       wsconsctl could be smarter about not showing edid
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Sep 19 23:30:00 +0000 2026
>Originator:     Valery Ushakov
>Release:        NetBSD 11.0
>Organization:
>Environment:
NetBSD omena 11.0 NetBSD 11.0 (GENERIC) #0: Thu Jul 30 15:23:12 UTC 2026  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64

>Description:
# wsconsctl -d -a
...
wsconsctl: "edid" not shown with -a; use "wsconsctl edid" to view.
...
# wsconsctl -d edid
wsconsctl: edid: no kernel support

>How-To-Repeat:

>Fix:
Not showing `edid` for `-a` is fine and dandy, but it would be nicer
to figure out whether it's supported and if it's not, then print "no
kernel support" right away or, may be even better, print nothing.