arm64: dts: qcom: sdm845-oneplus: remove devinfo-size from ramoops node

This property doesn't exist in Linux kernel.

Fixes: 288ef8a4 ("arm64: dts: sdm845: add oneplus6/6t devices")
Reviewed-by: Caleb Connolly <caleb@connolly.tech>
Signed-off-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211011200138.115688-1-david@ixit.cz