ARM: dts: qcom: ipq8064-rb3011: fix nand node validation

The devicetree documentation for the nand node requires the subnode be
called nand@ and no compatible is needed.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221013190657.48499-1-luca@z3ntu.xyz