dt-bindings: mmc: owl: add compatible string actions,s700-mmc

dt-bindings: mmc: owl: add compatible string actions,s700-mmc

The commit adds a new SoC specific compatible string "actions,s700-mmc"
in combination with more generic string "actions,owl-mmc".

Placement order of these strings should abide by the principle of
"from most specific to most general".

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
Link: https://lore.kernel.org/r/1599801849-6071-1-git-send-email-amittomer25@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>