msm: npu: Add firmware debug mode support

In order to support debugging npu firmware, driver can be switched
to firmware debug mode via debugfs. In this mode, driver is able to
pause firmware when it's booting and the timeout period for all IPC
commands is increased.

Change-Id: I4ff9e6bff7e95766d48a86be3e0036edfcbe5f62
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>