add phase-[1-6].[ds|nmon|vm] files to .gitignore

tests added    : no
tests run      : no
performance    : no change
release note   : none, internal change only
fast trackable : YES

Change-Id: I9d97aba7d8973bdf72bde978df99b031483a7477
Reviewed-on: https://gerrit.franz.com:9080/2913
Reviewed-by: Ahmon Dancy <dancy@franz.com>
Reviewed-by: John O'Rourke <jor@franz.com>
Tested-by: Kevin Layer <layer@franz.com>