Mark res_smdi/res_adsi as 'core' supported modules

Recently, various issues surrounding weak symbols have caused problems with
modules that rely on that feature to be enabled in menuselect.  This includes
app_voicemail and chan_dahdi, as they both rely upon res_smdi and res_adsi,
which, in certain circumstances, may not be enabled by default in menuselect.

Because res_smdi/res_adsi are dependencies for chan_dahdi/app_voicemail, this
patch marks both as 'core' supported modules.  This will allow both
app_voicemail and chan_dahdi to be enabled as well, regardless of whether or
not that system supports weak symbols.

(issue AST-900)
Reported by: Thomas Arimont

(issue AST-885)
Reported by: Denis Alberto Martinez
........

Merged revisions 368894 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 368895 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@368896 65c4cc65-6c06-0410-ace0-fbb531ad65f3