arm64: dts: meson: fix broken wifi node for Khadas VIM3L

arm64: dts: meson: fix broken wifi node for Khadas VIM3L

move &sd_emmc_a ... from /* */ commented area, because cant load wifi fw
without sd-uhs-sdr50 option on VIM3L

[   11.686590] brcmfmac: brcmf_chip_cores_check: CPU core not detected
[   11.696382] brcmfmac: brcmf_sdio_probe_attach: brcmf_chip_attach failed!
[   11.706240] brcmfmac: brcmf_sdio_probe: brcmf_sdio_probe_attach failed
[   11.715890] brcmfmac: brcmf_ops_sdio_probe: F2 error, probe failed -19...
[   13.718424] brcmfmac: brcmf_chip_recognition: chip backplane type 15 is not supported

Signed-off-by: Artem Lapkin <art@khadas.com>
Fixes: f1bb924e8f5b ("arm64: dts: meson: fix mmc0 tuning error on Khadas VIM3")
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20210129085041.1408540-1-art@khadas.com