thermal/powerclamp: fix missing newer package c-states

Package C8 to C10 was introduced in newer Intel CPUs, we need to
include them in the package c-state residency calculation.
Otherwise, idle injection target is not accurately maintained by
the closed control loop.

Also cleaned up the code to make it scale better with large number
of c-states.

Reported-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>