[][MAC80211][infra][Add slot0 node under pcie0 node]

[Description]
Add slot0 node under pcie0 node

MT76 driver uses of_get_child_by_name API to enable SingSKU/Flash Mode.
PCIe WiFi device on MT7986 fails to get because there is no slot0 node.

[Release-log]
N/A

Change-Id: I3d25a522a016c155b2439f43930f5d1420e0fd2c
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6056897
1 file changed