iio:accel:stk8312: add triggered buffer dependency

Add the still missing dependencies for triggered buffer support.

Fixes: 	95c12bba ("iio: accel: Add buffer mode for Sensortek STK8312")
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Reviewed-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/accel/Kconfig

@@ -140,6 +140,8 @@ config MMA9553
 config STK8312
 	tristate "Sensortek STK8312 3-Axis Accelerometer Driver"
 	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to get support for the Sensortek STK8312 3-axis
 	  accelerometer.