Merge branch 'realtek-external-phy-clock'

Detlev Casanova says:

====================
net: phy: realtek: Support external PHY clock

Some PHYs can use an external clock that must be enabled before
communicating with them.

Changes since v3:
 * Do not call genphy_suspend if WoL is enabled.
Changes since v2:
 * Reword documentation commit message
Changes since v1:
 * Remove the clock name as it is not guaranteed to be identical across
   different PHYs
 * Disable/Enable the clock when suspending/resuming
====================

Signed-off-by: David S. Miller <davem@davemloft.net>