phy: fix kdoc warning

Kdoc does not like it when multiline comment follows the networking
style of starting right on the first line:

include/linux/phy.h:869: warning: Function parameter or member 'config_intr' not described in 'phy_driver'

Link: https://lore.kernel.org/r/20201215063750.3120976-1-kuba@kernel.org


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