chore, update um-apfmon.c's file header

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, adapt um-apfmon to new unserding API

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, re-enable the build of the um-apfmon tool

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'tool/um-apfmon' into next

* tool/um-apfmon:
  chore, re-enable the build of the um-apfmon tool
  minor, adapt um-apfmon to new unserding API
  chore, update um-apfmon.c's file header
Merge branch 'next'

* next:
  chore, re-enable the build of the um-apfmon tool
  minor, adapt um-apfmon to new unserding API
  chore, update um-apfmon.c's file header