drivers: thermal: virtual-sensor: Add new virtual sensor for MSM8917

Add new virtual sensor definition for penta-cpu-max-step for MSM8917.
This virtual sensor can be used to monitor the overall temperature
of CPU cluster device.

Change-Id: I6a587b42cb4a474e1ce53ebbf893bbc168f22be4
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>
Signed-off-by: Archana Sriram <apsrir@codeaurora.org>