msm: npu: Continue npu_probe() when !DEBUG_FS

npu_probe() should not be dependent on DEBUG_FS
API's returning success. Continue device probe,
when DEBUG_FS is disabled.

Change-Id: I2c32c2f96a7cec9847ce5f8c2082393e77a2ad7e
Signed-off-by: Prateek Sood <prsood@codeaurora.org>