drivers: thermal: virtual-sensor: Add new gpu virtual sensor for SDMSHRIKE

Add new virtual sensor definition for quad-gpuss-max-step for SDMSHRIKE.
This virtual sensor can be used to monitor the overall temperature of
GPU subsystem.

Change-Id: I25702d94a5d6c64a7aa57f4aaa0a8012fc1bcdae
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>