mfd: Add ADP5520/ADP5501 driver

Base driver for Analog Devices ADP5520/ADP5501 MFD PMICs

Subdevs:
LCD Backlight   : drivers/video/backlight/adp5520_bl.c
LEDs            : drivers/led/leds-adp5520.c
GPIO            : drivers/gpio/adp5520-gpio.c (ADP5520 only)
Keys            : drivers/input/keyboard/adp5520-keys.c (ADP5520 only)

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 7df3bcf..b1d5370 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -174,6 +174,16 @@
 	  individual components like LCD backlight, voltage regulators,
 	  LEDs and battery-charger under the corresponding menus.
 
+config PMIC_ADP5520
+	bool "Analog Devices ADP5520/01 MFD PMIC Core Support"
+	depends on I2C=y
+	help
+	  Say yes here to add support for Analog Devices AD5520 and ADP5501,
+	  Multifunction Power Management IC. This includes
+	  the I2C driver and the core APIs _only_, you have to select
+	  individual components like LCD backlight, LEDs, GPIOs and Kepad
+	  under the corresponding menus.
+
 config MFD_WM8400
 	tristate "Support Wolfson Microelectronics WM8400"
 	select MFD_CORE