ARM: dts: omap3430-sdp: add dip switch information for MMC operation

MMC 8 bit mode operation depends on dip switch setting which is not
obvious - The current board file has this description. However, with
removal of the board file in the future, this information will be lost
and has to be rediscovered.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Benoit Cousson <bcousson@baylibre.com>

arch/arm/boot/dts/omap3430-sdp.dts

@@ -34,6 +34,10 @@ twl: twl@48 {
 &mmc1 {
 	vmmc-supply = <&vmmc1>;
 	vmmc_aux-supply = <&vsim>;
+	/*
+	 * S6-3 must be in ON position for 8 bit mode to function
+	 * Else, use 4 bit mode
+	 */
 	bus-width = <8>;
 };