ARM: ixp4xx: Delete the Goramo MLR boardfile

This board is replaced with the corresponding device tree.

Also delete dangling platform data file only used by this
boardfile and nothing else.

Cc: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220211223238.648934-3-linus.walleij@linaro.org


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