drm/radeon: use packet2 for nop on hawaii with old firmware
drm/radeon: use packet2 for nop on hawaii with old firmware

Older firmware didn't support the new nop packet.

v2 (Andreas Boll):
 - Drop usage of packet3 for new firmware

Signed-off-by: Alex Deucher <08dc22c6156113f2deff178e35e3ed9b24d6af9e@amd.com>
Reviewed-by: Christian König <c7ea837d7a46effe4232b086213468b8b31643bf@amd.com> (v1)
Signed-off-by: Andreas Boll <041cac00e0cb793452cecf5c52a77db13d069cf3@gmail.com>
Cc: 4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs