net/asterisk18: Add back g729 files distinfo

I removed these by mistake in commit 1e67882380f4

PR: 257478
Reported by: OlivierW <olivierw1+bugzilla-freebsd@hotmail.com>
MFH: 2021Q3

(cherry picked from commit 8f0389e64746725f0ed2e73c1a661f2c5d9ca778)