[][kernel][mt7988][dts][Fix typo for spi1]

[Description]
Fix typo for spi1, group spi1_1 is not supported.

[Release-log]
N/A

Change-Id: I6770395165b760c88a897207e784f069fd2094e3
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7144186
17 files changed