Staging: iio: add digital compass hmc5843 driver

Adding support for the Honeywell HMC5843. The interface to the device is
i2c

TODO:
Adding the documentation
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/Kconfig

@@ -44,6 +44,7 @@ source "drivers/staging/iio/adc/Kconfig"
 source "drivers/staging/iio/gyro/Kconfig"
 source "drivers/staging/iio/imu/Kconfig"
 source "drivers/staging/iio/light/Kconfig"
+source "drivers/staging/iio/magnetometer/Kconfig"
 
 source "drivers/staging/iio/trigger/Kconfig"
 

drivers/staging/iio/Makefile

@@ -15,3 +15,4 @@ obj-y += gyro/
 obj-y += imu/
 obj-y += light/
 obj-y += trigger/
+obj-y += magnetometer/

drivers/staging/iio/magnetometer/Kconfig

+#
+# Magnetometer sensors
+#
+comment "Magnetometer sensors"
+
+config SENSORS_HMC5843
+	tristate "Honeywell HMC5843 3-Axis Magnetometer"
+	depends on I2C
+	help
+	  Say Y here to add support for the Honeywell HMC 5843 3-Axis
+	  Magnetometer (digital compass).
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called hmc5843
+

drivers/staging/iio/magnetometer/Makefile

+#
+# Makefile for industrial I/O Magnetometer sensors
+#
+
+obj-$(CONFIG_SENSORS_HMC5843)	+= hmc5843.o