Revert "net: phy: dp83867: perform soft reset and retain established link"

This reverts commit da9ef50f.

This fixes a regression in which the link would come up, but no
communication was possible.

The reverted commit was also removing a comment about
DP83867_PHYCR_FORCE_LINK_GOOD, this is not added back in this commits
since it seems that this is unrelated to the original code change.

Closes: https://lore.kernel.org/all/ZGuDJos8D7N0J6Z2@francesco-nb.int.toradex.com/
Fixes: da9ef50f

 ("net: phy: dp83867: perform soft reset and retain established link")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Praneeth Bajjuri <praneeth@ti.com>
Link: https://lore.kernel.org/r/20230619154435.355485-1-francesco@dolcini.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>