net: ethernet: mtk_eth_soc: fix supported_interface set after phylink_create

net: ethernet: mtk_eth_soc: fix supported_interface set after phylink_create

Everything configured in phylink_config it's assumed to be set before
calling phylink_create() to permit correct parsing of all the different
modes and capabilities.

Commit 51cf06ddafc9 ("net: ethernet: mtk_eth_soc: add support for MT7988
internal 2.5G PHY") while introducing support for 2.5G phy for MT7988,
probably due to an auto-rebase, placed the configuration of the INTERNAL
interface mode for the supported_interfaces for phylink_config right after
phylink_create() introducing a possible problem with supported interfaces
parsing.

While this doesn't currently create any problem/bug, move setting this bit
before phylink_create() to prevent any possible regression in future code
change in phylink core.

Fixes: 51cf06ddafc9 ("net: ethernet: mtk_eth_soc: add support for MT7988 internal 2.5G PHY")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/20260615151106.15438-1-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>