doc: Add a manpage for the smsq utility

This patch adds a manpage for the smsq utility. Note that this is one of
the patches the Debian distro applies for the Asterisk project, as per
ASTERISK-24191.

Review: https://reviewboard.asterisk.org/r/3895/

ASTERISK-24171 #close
Reported by: Jeremy Laine
patches:
  smsq.8 uploaded by Jeremy Laine (License 6561)
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Merged revisions 422376 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 422377 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 422378 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 422379 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@422380 65c4cc65-6c06-0410-ace0-fbb531ad65f3