ASoC: SOF: loader: Add debug box region

This patch adds an IPC initiated debug box region in the snd_sof_dev
structure, defined in soc/sof/sof-priv.h. It is initialized at loading,
in the sof_get_windows function from soc/sof/loader.c, in a similar manner
with the stream box and host box.

This region is useful because the firmware will put an error message
here so the kernel can read it in case of a dsp oops.

Signed-off-by: Iulian Olaru <iulianolaru249@yahoo.com>
Reviewed-by: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://lore.kernel.org/r/20200825235854.1588034-5-ranjani.sridharan@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>