net: stmmac: rk: avoid phy_power_on()

net: stmmac: rk: avoid phy_power_on()

In https://lore.kernel.org/netdev/aDne1Ybuvbk0AwG0@shell.armlinux.org.uk/
I requested that a follow-up patch to change the name of dwmac-rk's
phy_power_on() function, which clashes with the drivers/phy function
of the same name. This can cause confusion when grepping for this
function name, or when reviewing code. Thankfully, stmmac doesn't make
use of drivers/phy which saves this from compile errors.

However, as is the usual case when a request is made as part of a
review, if the review leads to successful application of the patch the
author doesn't bother following up with any such requests, and so the
problem falls back onto the reviewer to address... so here is the
solution.

Rename dwmac-rk's function to rk_phy_power_ctl(), as the function both
powers up and down.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vkL1i-00000005usD-3lhz@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>