Staging: iio: Fix up the module build.

Both the max1363 and lis3l02dq modules rely on IIO trigger support in
their ring buffer implementations, which is presently a separate config
option. In the case of IIO_RING_BUFFER=y and IIO_TRIGGER=n, we end up
with the following:

ERROR: "iio_trigger_attach_poll_func" [drivers/staging/iio/adc/max1363.ko] undefined!
ERROR: "iio_trigger_dettach_poll_func" [drivers/staging/iio/adc/max1363.ko] undefined!
ERROR: "iio_trigger_unregister" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_trigger_notify_done" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_trigger_read_name" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_trigger_poll" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_trigger_attach_poll_func" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_trigger_register" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_free_trigger" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_trigger_dettach_poll_func" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
ERROR: "iio_allocate_trigger" [drivers/staging/iio/accel/lis3l02dq.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

This adds an IIO_TRIGGER select for these two drivers conditional on
IIO ring buffer support. Caught with an SH randconfig in -next.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/accel/Kconfig

@@ -13,6 +13,7 @@ config KXSD9
 config LIS3L02DQ
 	tristate "ST Microelectronics LIS3L02DQ Accelerometer Driver"
 	depends on SPI
+	select IIO_TRIGGER if IIO_RING_BUFFER
 	help
 	  Say yes here to build SPI support for the ST microelectronics
 	  accelerometer. The driver supplies direct access via sysfs files

drivers/staging/iio/adc/Kconfig

@@ -6,6 +6,7 @@ comment "Analog to digital convertors"
 config MAX1363
 	tristate "MAXIM max1363 ADC driver"
 	depends on I2C
+	select IIO_TRIGGER if IIO_RING_BUFFER
 	help
 	  Say yes here to build support for many MAXIM i2c analog to digital
 	  convertors (ADC). (max1361, max1362, max1363, max1364, max1136,