regmap: Don't attempt block writes when syncing cache on single_rw devices

regmap: Don't attempt block writes when syncing cache on single_rw devices

commit 5c1ebe7f73f9166893c3459915db8a09d6d1d715 upstream.

If the device can't support block writes then don't attempt to use raw
syncing which will automatically generate block writes for adjacent
registers, use the existing _single() block syncing implementation.

Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>