Drop the kerneldoc markup for connectivity_check() as it's an
static helper function. Fixes the following make W=1 warning:

sound/hda/hdac_i915.c:80: warning: Function parameter or member 'i915' not described in 'connectivity_check'
sound/hda/hdac_i915.c:80: warning: Function parameter or member 'hdac' not described in 'connectivity_check'

Fixes: 7b882fe3 ('ALSA: hda - handle multiple i915 device instances')
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200924161027.3402260-1-kai.vehmanen@linux.intel.comSigned-off-by: Takashi Iwai <tiwai@suse.de>