ARM: dts: qcom: msm8226: Add more SoC bits

Add nodes for sdhc, uart4, i2c, scm, smem, rpm-requests including
dependencies.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
[bjorn: Moved other nodes before "soc" to keep things alphabetical]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210911232707.259615-5-luca@z3ntu.xyz