[][kernel][mt7986][eth][Change GMAC0/1 DTS configuratoin for HSGMII]

[Description]
Change GMAC0/1 DTS configuratoin for HSGMII.

1. Change GMAC0/1 DTS configuration to phy-handle.
2. Change PHY reset to bus level reset.

[Release-log]
N/A

Change-Id: I3b59f4e62aa5d2348f229047624db4a298785ff3
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6376188
12 files changed