ARM: dts: ux500: samsung-golden: Add WiFi

ARM: dts: ux500: samsung-golden: Add WiFi

samsung-golden uses a BCM4334 WiFi+BT combo chip, connected to SDIO.
It is supported by the brcmfmac driver in mainline,
so we only need to set up the device tree to make it work correctly.

Note: brcmfmac requires (proprietary) firmware + a device-specific
NVRAM file. Both can be extracted from the stock Android system
used on samsung-golden:
  - /system/etc/wifi/bcmdhd_sta.bin_b2   -> /lib/firmware/brcm/brcmfmac4334-sdio.bin
  - /system/etc/wifi/nvram_net.txt_GPIO4 -> /lib/firmware/brcm/brcmfmac4334-sdio.samsung,golden.txt

brcmfmac4334-sdio.bin from linux-firmware also seems to work,
but results in occasional errors for some reason.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20191219202052.19039-8-stephan@gerhold.net
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>