MAINTAINERS: update maintainers info
MAINTAINERS: update maintainers info

adds the mailing list address for bluetooth 6loWPAN and
IEEE-802.15.4 subsystems. Also adds web page info.

Signed-off-by: Varka Bhadram <2af78e27b8c15f3929acd171eee40b9b9bcbd73c@cdac.in>
Signed-off-by: Marcel Holtmann <44592b4eea36663c86b994bb0ea99d15309c1c7d@holtmann.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs