ARM: dts: ux500: skomer: Pull down SDI2 FBCLK

The feedback clock on SDI2 needs to be pulled down on
this machine.

Link: https://lore.kernel.org/r/20201111002513.2271351-1-linus.walleij@linaro.org


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>