Current script assumes last cpu would map to last cluster in cpu-map.
But it might not true always, device-tree can map cpus in different
order than its actual number. i.e. cpus0-3 could be part on cluster#1,
and cpus4-7 maps to cluster#0, in this case last cluster id is 0 and
breaks above assumption.

Fix this by dynamically extending the cluster list.

Change-Id: I907d89e33a1f57b656c6df374a23e18b2d2c42fa
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>