net: enetc: remove invalid code from enetc4_pl_mac_link_up()

When adding phylink MAC operations support to the NETC switch driver,
Russell King pointed out several pieces of invalid logic in the
.mac_link_up() implementation (see [1] and [2]):

1) Half-duplex backpressure is not supported by the kernel, Ethernet
   relies on packet dropping for congestion management.

2) phylink_autoneg_inband() is unnecessary, as RGMII in-band status is
   not supported.

3) TX and RX pause are disabled in half-duplex mode, so there is no
   need to override them in .mac_link_up().

The same invalid logic is also present in enetc4_pl_mac_link_up(), so
remove the invalid code from it.

Given enetc4_set_hd_flow_control() is removed, pf->caps.half_duplex has
also become useless and should therefore be removed as well.

Link: https://lore.kernel.org/imx/acEIQqI-_oyCym8O@shell.armlinux.org.uk/ # 1
Link: https://lore.kernel.org/imx/acEFwqmAvWls_9Ef@shell.armlinux.org.uk/ # 2
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260720014317.1059359-9-wei.fang@oss.nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions