ARM: dts: sunxi: Fix BCM43xx node name

"bcrmf" is a typo and "wifi" is the preferred form to describe
such node, so change it accordingly.

Reported-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>