r8169: clear TX LPI on RTL8168h at link up after phylink conversion

Commit 3cdeaef1754a ("r8169: disable EEE on RTL8168h/8111h") disables
EEE on RTL_GIGA_MAC_VER_46 with phy_disable_eee() but keeps the version
EEE-capable, so that link up still calls rtl_enable_tx_lpi(tp, false)
and clears the MAC TX-LPI bits (ERI 0x1b0[1:0]). rtl_hw_start_8168h_1()
does not clear them, so a warm reboot from an EEE-active state could
otherwise leave TX-LPI asserted while the PHY no longer negotiates EEE.

In net-next, commit 8a3c76523e44 ("r8169: add support for phylink")
moved link handling to phylink, and rtl_mac_link_up() does not touch
the TX-LPI bits. The merge of net into net-next kept the
phy_disable_eee() quirk and its comment, but not the link-up clear it
depends on. The only remaining clear is rtl_mac_disable_tx_lpi(), which
phylink calls from phylink_deactivate_lpi() only after
phylink_activate_lpi() has enabled LPI. With EEE disabled on this chip
that never happens, so the bits are never cleared and the comment in
r8169_mdio_register() no longer holds.

Clear TX-LPI explicitly in rtl_mac_link_up() for RTL_GIGA_MAC_VER_46.

Fixes: f49defea7668 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
Link: https://lore.kernel.org/all/0e0b727e94d046b19ad463e7a1a9fe68@realsil.com.cn/
Signed-off-by: Sasha Levin <sashal@kernel.org>
Link: https://patch.msgid.link/20261020161543.3712208-1-sashal@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>