arm64: dts: meson-gx-p23x-q20x: Fix Wifi node name

bcrmf -> brcmf -> wifi

Fixes: bb51b535 ("ARM64: dts: Add support for Meson GXM")
Cc: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>