pinctrl: berlin: comment the spi functions

Add comments for the SPI functions, to distinguish CLK, SDI, SDO and
C{0,1,2,3}n.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/berlin/berlin-bg2cd.c b/drivers/pinctrl/berlin/berlin-bg2cd.c
index 3fc05fb..a8b9808 100644
--- a/drivers/pinctrl/berlin/berlin-bg2cd.c
+++ b/drivers/pinctrl/berlin/berlin-bg2cd.c
@@ -68,17 +68,17 @@
 		BERLIN_PINCTRL_FUNCTION(0x1, "twsi1"),
 		BERLIN_PINCTRL_FUNCTION(0x2, "gpio")),
 	BERLIN_PINCTRL_GROUP("G8", 0x00, 0x3, 0x10,
-		BERLIN_PINCTRL_FUNCTION(0x0, "spi1"),
+		BERLIN_PINCTRL_FUNCTION(0x0, "spi1"), /* SS0n */
 		BERLIN_PINCTRL_FUNCTION(0x1, "gpio")),
 	BERLIN_PINCTRL_GROUP("G9", 0x00, 0x3, 0x13,
 		BERLIN_PINCTRL_FUNCTION(0x0, "gpio"),
-		BERLIN_PINCTRL_FUNCTION(0x1, "spi1"),
+		BERLIN_PINCTRL_FUNCTION(0x1, "spi1"), /* SS1n/SS2n */
 		BERLIN_PINCTRL_FUNCTION(0x2, "twsi0")),
 	BERLIN_PINCTRL_GROUP("G10", 0x00, 0x2, 0x16,
-		BERLIN_PINCTRL_FUNCTION(0x0, "spi1"),
+		BERLIN_PINCTRL_FUNCTION(0x0, "spi1"), /* CLK */
 		BERLIN_PINCTRL_FUNCTION(0x1, "gpio")),
 	BERLIN_PINCTRL_GROUP("G11", 0x00, 0x2, 0x18,
-		BERLIN_PINCTRL_FUNCTION(0x0, "spi1"),
+		BERLIN_PINCTRL_FUNCTION(0x0, "spi1"), /* SDI/SDO */
 		BERLIN_PINCTRL_FUNCTION(0x1, "gpio")),
 	BERLIN_PINCTRL_GROUP("G12", 0x00, 0x3, 0x1a,
 		BERLIN_PINCTRL_FUNCTION(0x0, "usb1"),