dt-bindings: mmc: sdhci-of-aspeed: Update example ranges property

The example node in the binding uses the AST2500 compatible string for
the SD controller with a 64kiB ranges property, but the SD controller is
allocated 128kiB of MMIO space according to the AST2500 datasheet. Fix
the example to correctly reflect the hardware in the AST2500, however it
should be noted that the MMIO region is reduced to 64kiB in the AST2600
where a second SD controller block has been introduced into the address
space.

Also add the IBM copyright header that I left out of the initial patch.

Suggested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>