drivers/gpu: Fix misalignment in comment block

This patch fixes a warning from checkpatch by ensuring the trailing */ is
aligned with the rest of the *, improving readability.

Co-developed-by: Lucas Antonio <lucasantonio.santos@usp.br>
Signed-off-by: Lucas Antonio <lucasantonio.santos@usp.br>
Signed-off-by: Bruno Rocha Levi <brunolevilevi@usp.br>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>