Mark BROKEN_armv6 and BROKEN_armv7

BROKEN_armv6 was removed in r444870 by accident.
And Mark Linimon mentioned same error on armv7.

Notified by: linimon
Reference: http://beefy8.nyi.freebsd.org/data/head-armv6-default/p461852_s329284/logs/errors/bash-completion-2.7,1.log