Hey guys,

the attached patch updates the list of whitelisted ThinkPad models with 
dual fan support.

The changes were tested on my ThinkPad T15g Gen 2. According to Lenovo, 
the BIOS version is the same for the P15 Gen 2 and the P17 Gen 2 ( 
https://pcsupport.lenovo.com/us/en/downloads/ds551321-bios-update-utility-bootable-cd-for-windows-10-64-bit-thinkpad-p15-gen-2-p17-gen-2-t15g-gen-2 
).

I also added the P15v Gen 2 and T15p Gen 2 to the whitelist based on the 
BIOS version listed on the Lenovo homepage ( 
https://pcsupport.lenovo.com/us/en/downloads/ds551356-bios-update-utility-bootable-cd-for-windows-10-64-bit-thinkpad-p15v-gen-2-t15p-gen-2 
). The first generation had two fans and where covered by the whitelist 
entry for the P15 Gen 2. As the second generation has two fans, too, I 
made that change for completeness.

To apply the changes before it's merged in the mainline linux kernel, I 
made a little dkms patch: 
https://github.com/dreschner/thinkpad_acpi-dual-fan-patch

Best reguards,
David