net: phy: phy_interface_t: Fix RGMII_TXID code comment

Fix copy-paste error in the code comment for Interface Mode definitions.
The code refers to Internal TX delay, not Internal RX delay. It was likely
copied from the line above this one.

Signed-off-by: Ihor Matushchak <ihor.matushchak@foobox.net>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250316071551.9794-1-ihor.matushchak@foobox.net


Signed-off-by: Jakub Kicinski <kuba@kernel.org>