arm64: dts: qcom: msm8916: Add ddr support to sdhc1

This adds mmc-ddr-1_8v support to DT for sdhc1 of msm8916.

Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>