Documentation: dt-bindings: Add aliases information for Exynos7 pin controllers

Adding list of aliases for supported Exynos7 pin controller blocks.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/samsung-pinctrl.txt

@@ -171,6 +171,16 @@ Aliases:
 All the pin controller nodes should be represented in the aliases node using
 the following format 'pinctrl{n}' where n is a unique number for the alias.
 
+Aliases for controllers compatible with "samsung,exynos7-pinctrl":
+- pinctrl0: pin controller of ALIVE block,
+- pinctrl1: pin controller of BUS0 block,
+- pinctrl2: pin controller of NFC block,
+- pinctrl3: pin controller of TOUCH block,
+- pinctrl4: pin controller of FF block,
+- pinctrl5: pin controller of ESE block,
+- pinctrl6: pin controller of FSYS0 block,
+- pinctrl7: pin controller of FSYS1 block,
+
 Example: A pin-controller node with pin banks:
 
 	pinctrl_0: pinctrl@11400000 {