iio: cros_ec: Use default frequencies when EC returns invalid information

iio: cros_ec: Use default frequencies when EC returns invalid information

Minimal and maximal frequencies supported by a sensor is queried.
On some older machines, these frequencies are not returned properly and
the EC returns 0 instead.
When returned maximal frequency is 0, ignore the information and use
default frequencies instead.

Fixes: ae7b02ad2f32 ("iio: common: cros_ec_sensors: Expose cros_ec_sensors frequency range via iio sysfs")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20200630153730.3302889-1-gwendal@chromium.org
CC: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>