drm/i915/audio: Fix audio enumeration issue on BXT

On Apollolake, with stress test warm reboot, audio card was not getting
enumerated after reboot. This was a spurious issue happening on
Apollolake. HW codec and HD audio controller link was going out of sync
for which there was a fix in i915 driver but was not getting invoked for
BXT. Extending this fix to BXT as well.

Tested on apollolake chromebook by stress test warm reboot with 2500
iterations.

Bspec: 21829

Signed-off-by: Gaurav K Singh <gaurav.k.singh@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1522946544-11524-1-git-send-email-gaurav.k.singh@intel.com