iio: hid-sensors: select IIO_TRIGGERED_BUFFER under HID_SENSOR_IIO_TRIGGER

iio: hid-sensors: select IIO_TRIGGERED_BUFFER under HID_SENSOR_IIO_TRIGGER

During commit 067fda1c065ff ("iio: hid-sensors: move triggered buffer
setup into hid_sensor_setup_trigger"), the
iio_triggered_buffer_{setup,cleanup}() functions got moved under the
hid-sensor-trigger module.

The above change works fine, if any of the sensors get built. However, when
only the common hid-sensor-trigger module gets built (and none of the
drivers), then the IIO_TRIGGERED_BUFFER symbol isn't selected/enforced.

Previously, each driver would enforce/select the IIO_TRIGGERED_BUFFER
symbol. With this change the HID_SENSOR_IIO_TRIGGER (for the
hid-sensor-trigger module) will enforce that IIO_TRIGGERED_BUFFER gets
selected.

All HID sensor drivers select the HID_SENSOR_IIO_TRIGGER symbol. So, this
change removes the IIO_TRIGGERED_BUFFER enforcement from each driver.

Fixes: 067fda1c065ff ("iio: hid-sensors: move triggered buffer setup into hid_sensor_setup_trigger")
Reported-by: Thomas Deutschmann <whissi@gentoo.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20210414084955.260117-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>