[][mt7981: remove spi dummy clk node]

[Description]
Remove spi dummy clk node for mt7981

[Release-log]
N/A

Change-Id: Ia3ac7676a90a52f63d028dd260dace714cee1264
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5336913
1 file changed