kern/56946: uslsa(4) seems to not work on big endian machines

[martin%NetBSD.org@localhost]

>Number:         56946
>Category:       kern
>Synopsis:       uslsa(4) seems to not work on big endian machines
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 29 11:00:00 +0000 2022
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.99
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD big-apple.aprisoft.de 9.99.99 NetBSD 9.99.99 (POWERMAC_G5.MP) #65: Thu Jul 28 16:26:57 CEST 2022 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/macppc/compile/POWERMAC_G5.MP macppc
Architecture: powerpc
Machine: macppc
>Description:

From experiecnce with a tiny, non representative sample of two machines
(macppc, sparc64) and a single device (odriod console adapter) it seems
that uslsa(4) does not work on big endian machines. The same setup
works fine with an amd64 notebook runing current from the same sources.

>How-To-Repeat:
Try to use serial console of some other machine connected via ucom @ uslsa

>Fix:
n/a