3rdparty/t9write: unpack.py: Fix ordering of unpack rules

Specific rules need to be executed in certain order. Wrap the
UNPACK_RULES to a list, so the order of the rules can be specified.

Change-Id: Ib160a814b49ed25fd0ed85337cfddf80afa0ccd7
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>