gen2/accelerator: Remove old attribute comments
gen2/accelerator: Remove old attribute comments

These attribute comments ought to have been removed when the attributes
were removed.

Signed-off-by: Alan Green <97e77871b5fcc4941bebceb4338c97c1fd149f8c@google.com>

google/CFU-Playground,google/CFU-Playground,google/CFU-Playground,google/CFU-Playground