freedreno/devices: Document an alias for FD644

While the blob driver calls this GPU A644, in kgsl (and internally) it is known as A662.
The chip_id also reflects this name.

A662 is a closer match to reality as we're talking about an A660-based GPU, but keep the name
we expose as FD644 to match the blob.

Signed-off-by: Valentine Burley <valentine.burley@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31328>

src/freedreno/common/freedreno_devices.py

@@ -729,7 +729,7 @@ add_gpus([
     ))
 
 add_gpus([
-        GPUId(chip_id=0x6060201, name="FD644"),
+        GPUId(chip_id=0x6060201, name="FD644"), # Called A662 in kgsl
     ], A6xxGPUInfo(
         CHIP.A6XX,
         [a6xx_base, a6xx_gen4],