port-evbarm/55515: config -x appends strange lines

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         55515
>Category:       port-evbarm
>Synopsis:       config -x appends strange lines
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-evbarm-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 24 11:05:00 +0000 2020
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current
>Organization:
>Environment:
System: NetBSD
Architecture: earmv7hf
Machine: evbarm
>Description:

Booting an evbarm-aarch64 image in qemu and running "config -x", the
output ends with the expected

  ### (end include "dev/usb/usbdevices.config")

followed by some unexpected lines:

  ARU_MBOX_OWNER 0x%x
  ARU_MBOX_OWNER 0x%x
  ARU_SMI_INTR 0x%x
  ARU_MBOX_DATA_OUT 0x%x
  ARU_MBOX_CMD 0x%x
  REG:        %08x

With evbarm-earmv7hf, no actual kernel configuration is printed,
presumably because "options INCLUDE_CONFIG_FILE" is disabled, but
similar strange lines containing 0x%x format strings are.

This does not happen on amd64.

>How-To-Repeat:

>Fix: