msm: npu: Add asynchronous ioctl support

In order to improve the NPU performance, ioctl commands like
execute_network need to be executed in asynchronous mode to
allow user applications to run multiple operations parallelly.

Change-Id: I8cf4f20569539667a0eda6a0b8e3ec610ddde210
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>