devicetree: bindings: firmware: add ipq806x to qcom_scm

Add ipq806x to compatible list in qcom_scm Documentation

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20200311130918.753-2-ansuelsmth@gmail.com


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>