ASoC: wcd-dsp-mgr: force crash upon collecting ramdumps

In case of WDSP fatal errors, subsystem restart is done to reset the
WDSP. Currently, the driver performs subsystem restart silently and
does not cause devie crash. Add debugfs property 'panic_on_error'
to indicate the driver to induce BUG_ON to aid debugging. The BUG_ON
is done only when the debugfs property is explicity set through
debugfs. If not set, the driver will continue without crashing. The
below command can be used to set the debugfs property.

echo Y > /sys/kernel/debug/wdsp_mgr/panic_on_error

CRs-fixed: 2029058
Change-Id: I1442cc59e1819c3b0abd4c4776f4b32ba63d59e2
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>