ARM: dts: msm: add third cluster support for Kona

Kona supports three clusters, update cpu map to reflect the same.
While at it, add capacity-dmips-mhz property to support EAS on Kona.

Change-Id: I7110fade7389aa4ecbcceec6dce3ff587409f446
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>