msm: npu: Don't allow ioctl cmds to be interrupted

When the ioctl is interrupted, it is difficult to
predict and handle the firmware state properly from
the kernel. This change is to keep ioctl cmds from
being interrupted.

Change-Id: I1377122d23e4a63438cc7a844aec56f7e8a9b4cf
Signed-off-by: dpyun <dpyun@codeaurora.org>