ARM: dts: at91: sama5d27_wlsom1: add wifi device

SAMA5D27 WLSOM1 boards has a WILC3000 device soldered. Add proper
device tree nodes for this.

[eugen.hristev: original author of this code]
[claudiu.beznea: adapt such that make dtbs_check is happy, remove status
 for wifi_pwrseq and wifi nodes]

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
[nicolas.ferre: original author of this code]
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20210825094055.642941-1-claudiu.beznea@microchip.com