iio: hid-sensors: Added Compass/Magnetometer 3D

Added usage id processing for Compass 3D. This uses IIO
interfaces for triggered buffer to present data to user
mode.This uses HID sensor framework for registering callback
events from the sensor hub.
Signed-off-by: srinivas pandruvada <srinivas.pandruvada@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/Kconfig

@@ -62,5 +62,6 @@ source "drivers/iio/frequency/Kconfig"
 source "drivers/iio/dac/Kconfig"
 source "drivers/iio/common/Kconfig"
 source "drivers/iio/gyro/Kconfig"
+source "drivers/iio/magnetometer/Kconfig"
 
 endif # IIO

drivers/iio/Makefile

@@ -18,3 +18,4 @@ obj-y += frequency/
 obj-y += dac/
 obj-y += common/
 obj-y += gyro/
+obj-y += magnetometer/

drivers/iio/magnetometer/Kconfig

+#
+# Magnetometer sensors
+#
+menu "Magnetometer sensors"
+
+config HID_SENSOR_MAGNETOMETER_3D
+	depends on HID_SENSOR_HUB
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select HID_SENSOR_IIO_COMMON
+	tristate "HID Magenetometer 3D"
+	help
+	  Say yes here to build support for the HID SENSOR
+	  Magnetometer 3D.
+
+endmenu

drivers/iio/magnetometer/Makefile

+#
+# Makefile for industrial I/O Magnetometer sensor drivers
+#
+
+obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o