ARM: dts: add EBI2 to the Qualcomm MSM8660 DTSI

This adds the external bus interface EBI2 to the MSM8660 device
tree, albeit with status = "disabled" so that devices actually
using EBI2 can turn it on if needed.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>