Merge pull request #11385 from AbhishekNR/show_cli

pimd, pim6d: Moving reusable code to common api for show CLI's.

diff --cc pimd/pim6_cmd.c
Simple merge

diff --cc pimd/pim_cmd.c
Simple merge

diff --cc pimd/pim_cmd_common.c
Simple merge

diff --cc pimd/pim_cmd_common.h
Simple merge