channel: Extend size of buffer for codecs in "core show channeltype" CLI command.

The static buffer for codecs when invoking the "core show channeltype" CLI command
did not have enough room for all codecs. This has been extended so it does.

ASTERISK-24542 #close
Reported by: snuffy
patches:
 channeltype-tech.diff submitted by snuffy (license 5024)

Review: https://reviewboard.asterisk.org/r/4204/


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/13@428632 f38db490-d61c-443f-a65b-d21fe96a405b