iio: Add a comment to about alphabetical order to Kconfigs and Makefiles

Keeping Makefile and Kconfig entries in alphabetical order usually works better
than just appending new entries at the end, since it reduces the amount of
conflicts. This patch adds a comment to the IIO Kconfig and Makefile files to
document that the entries should be kept in alphabetical order.

Also reorder those  entries which weren't in alphabetical order yet.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 2eced9d..dd6bd1b 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -1,6 +1,8 @@
 #
 # ADC drivers
 #
+# When adding new entries keep the list in alphabetical order
+
 menu "Analog to digital converters"
 
 config AD_SIGMA_DELTA
@@ -30,17 +32,20 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7298.
 
-config AD7923
-	tristate "Analog Devices AD7923 and similar ADCs driver"
+config AD7476
+	tristate "Analog Devices AD7476 and similar 1-channel ADCs driver"
 	depends on SPI
 	select IIO_BUFFER
 	select IIO_TRIGGERED_BUFFER
 	help
-	  Say yes here to build support for Analog Devices
-	  AD7904, AD7914, AD7923, AD7924 4 Channel ADCs.
+	  Say yes here to build support for Analog Devices AD7273, AD7274, AD7276,
+	  AD7277, AD7278, AD7475, AD7476, AD7477, AD7478, AD7466, AD7467, AD7468,
+	  AD7495, AD7910, AD7920, AD7920 SPI analog to digital converters (ADC).
+
+	  If unsure, say N (but it's safe to say "Y").
 
 	  To compile this driver as a module, choose M here: the
-	  module will be called ad7923.
+	  module will be called ad7476.
 
 config AD7791
 	tristate "Analog Devices AD7791 ADC driver"
@@ -66,21 +71,6 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called AD7793.
 
-config AD7476
-	tristate "Analog Devices AD7476 and similar 1-channel ADCs driver"
-	depends on SPI
-	select IIO_BUFFER
-	select IIO_TRIGGERED_BUFFER
-	help
-	  Say yes here to build support for Analog Devices AD7273, AD7274, AD7276,
-	  AD7277, AD7278, AD7475, AD7476, AD7477, AD7478, AD7466, AD7467, AD7468,
-	  AD7495, AD7910, AD7920, AD7920 SPI analog to digital converters (ADC).
-
-	  If unsure, say N (but it's safe to say "Y").
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called ad7476.
-
 config AD7887
 	tristate "Analog Devices AD7887 ADC driver"
 	depends on SPI
@@ -94,6 +84,18 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7887.
 
+config AD7923
+	tristate "Analog Devices AD7923 and similar ADCs driver"
+	depends on SPI
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Analog Devices
+	  AD7904, AD7914, AD7923, AD7924 4 Channel ADCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7923.
+
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on ARCH_AT91