ARM: dts: nspire: use lower case hex addresses in node unit addresses

Convert all hex addresses in node unit addresses to lower case to fix
dt_binding_check and dtc W=1 warnings.

Conversion was done using sed:

  $ sed -e 's/@\([a-zA-Z0-9_-]*\) {/@\L\1 {/' -i arch/arm/boot/dts/nspire*
  $ sed -e 's/<0x\([a-zA-Z0-9_-]*\) /<0x\L\1 /g' -i arch/arm/boot/dts/nspire*

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220317115542.450032-2-krzysztof.kozlowski@canonical.com