ARM: dts: qcom: ipq4019: Add SDHCI controller node

IPQ4019 has a built in SD/eMMC controller which is supported by the
SDHCI MSM driver, by the "qcom,sdhci-msm-v4" binding.
So lets add the appropriate node for it.

Signed-off-by: Robert Marko <robimarko@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>