drivers: qti-virtual-sensor: Add hexa cpu max virtual sensor for SDM429

Update MAX mode virtual sensors list with hexa core sensors for
SDM429. It enables thermal zone devicetree rule to use this sensor
for cpu mitigation.

Change-Id: If67d7af942398d13922a03ae2bf4178484537f96
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>