encoding: add doxygen for rlc_data_to_dl_append*

Change-Id: I6ead0f1d14a91c657448227e17438b49a54e6c4a
Reviewed-on: https://gerrit.osmocom.org/141
Tested-by: Jenkins Builder
Reviewed-by: Harald Welte <laforge@gnumonks.org>
1 file changed