msm: lpm-levels-of: fix accessing out of bound memory

CPU's lpm level kobjects are dynamically allocated based on the
number of CPU's in that cluster. The kobject's are then indexed
using the cpu number. This results in the driver writing to and
using memory not allocated to it. Fix this by using an index
starting from zero to index into the allocated kobject array.

CRs-fixed: 739886
Change-Id: I033590c89ad800087007ed6ba60fe558c2221767
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>