It turned out that the recent Intel HD-audio controller chips show a
significant stall during the system PM resume intermittently.  It
doesn't happen so often and usually it may read back successfully
after one or more seconds, but in some rare worst cases the driver
went into fallback mode.

After trial-and-error, we found out that the communication stall seems
covered by issuing the sync after each verb write, as already done for
AMD and other chipsets.  So this patch enables the write-sync flag for
the recent Intel chips, Skylake and onward, as a workaround.

Also, since Broxton and co have the very same driver flags as Skylake,
refer to the Skylake driver flags instead of defining the same
contents again for simplification.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=201901Reported-and-tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>