soc: qcom: qmi_interface: allocate high priority work queue

Some qmi clients have low latency requirement. In high system load
there may be scheduling delay in work queue which can delay qmi packet
delivery to qmi clients.

Adding high priority flag while allocating qmi work queue.

Change-Id: I64ba90777d3337849113ae4163f997bb781fbd40
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>