dell link no longer works 
@ADW: what do we want to do in such a case? Already checked the internet archive and couldn't find any cached versions.
/Sven
If a link is dead and there's no archive.org version, we just have to remove the link. It's unfortunate, but I don't see what else we can do.
Though it seems that page doesn't exist anymore, there is page with similar instructions Trusted Platform Module (TPM) Upgrade/Downgrade process for Windows 7 and 10 operating system Upgrade/Downgrade | Dell US. Exact instructions are
Go to https://www.dell.com/support/home/Products/?app=drivers and choose your product , in this case Laptops --> Latitude --> 7280 or directly to page https://www.dell.com/support/home/en-us/product-support/product/latitude-12-7280-laptop/drivers (according to above document it can also be applied to E7270 that also is in HCL)
Choose Operating System of your laptop, paying attention whether it is 64-bit or 32-bit
Choose category "Security" to filter results
Download utilities
Current standalone page for Dell TPM 1.2 Firmware Update Utility for 64-bit systems is https://www.dell.com/support/home/en-us/drivers/driversdetails?driverid=m8xg0&oscode=wt64a&productcode=latitude-12-7280-laptop and direct download link is https://dl.dell.com/FOLDER04468656M/1/DellTpm1.2_Fw5.81.2.1_V3_64.exe
Current standalone page for Dell TPM 2.0 Firmware Update Utility for 64-bit systems is https://www.dell.com/support/home/en-us/drivers/driversdetails?driverid=rf87d&oscode=wt64a&productcode=latitude-12-7280-laptop and direct download link is https://dl.dell.com/FOLDER04166647M/1/DellTpm2.0_Fw1.3.2.8_V1_64.exe
Though in the first link of this message only Dell Latitude E7270 is mentioned, if we click on "Compatible Systems" on TPM 1.2 utility page we can see that instructions are applicable also to Dell Latitude 7480, Dell Latitude E5470, Dell Latitude E5570, Dell Latitude E7270, Dell Latitude E7470. I mentioned these models because they already are in HCL but maybe it's better to mention all models that can be downgraded to TPM 1.2 for all viewers looking for their hardware.
Download links are the same for all models.
Thank you! I will point your post with the next update of the HCL.
/Sven