When both the accelerator device and SMMU are busy,
the processing time of the doorbell may be prolonged.
As a result, the doorbell may timeout, especially in the sva
scenario. Therefore, the doorbell timeout is increased.
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>