staging: iio: TAOS tsl258x: Device driver

Added suspend/resume functions.
Changed attribute names to match existing where applicable and updated
or documented new ABI as discussed.
Changed integration time ABI from using index (0 to 3) to use actual
gain values (1x,8x, etc.).
Removed various unused variables, declarations, and functions.
Revised code to accommodate different endianess (le16_to_cpu).
Updated error return codes in various functions.
Changed from mdelay to msleep after determining that longer wait would
be acceptable.

V5: Makefile and Kconfig cleanups by Jonathan Cameron.

Signed-off-by: Jon August Brenner <jbrenner@taosinc.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/iio/light/Kconfig b/drivers/staging/iio/light/Kconfig
index 36d8bbe..e9f3794 100644
--- a/drivers/staging/iio/light/Kconfig
+++ b/drivers/staging/iio/light/Kconfig
@@ -24,3 +24,9 @@
          in lux, proximity infrared sensing and normal infrared sensing.
          Data from sensor is accessible via sysfs.
 
+config TSL2583
+	tristate "TAOS TSL2580, TSL2581, and TSL2583 light-to-digital converters"
+	depends on I2C
+	help
+	 Provides support for the TAOS tsl2580, tsl2581, and tsl2583 devices.
+	 Access ALS data via iio, sysfs.