task #29499913

commit f362cdccca07c2b90fc4fac9bf13d9ce975e9aa7 upstream

When the device file "/dev/isst_interface" is not present, instead of
failing on access, check at the start and print a helpful warning.

Here CLX platform is an exception, which doesn't depend on the device
file. So continue for CLX platform.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NErwei Deng <erwei@linux.alibaba.com>
Reviewed-by: NArtie Ding <artie.ding@linux.alibaba.com>