An experimental test with the command below gives this error:
rk3188-bqedison2qc.dt.yaml: dwmmc@10218000: wifi@1:
'reg' is a required property

So fix this by adding a reg property to the brcmf sub node.
Also add #address-cells and #size-cells to prevent more warnings.

make ARCH=arm dtbs_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20200110134420.11280-1-jbx6244@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>