net: stmmac: sti: convert to stmmac_pltfr_pm_ops

net: stmmac: sti: convert to stmmac_pltfr_pm_ops

As we now have the plat_dat->init()/plat_dat->exit() populated which
have the required functionality on suspend/resume, we can now use
stmmac_pltfr_pm_ops which has methods that call these two functions.
Switch over to use this.

Doing so also fills in the runtime PM ops and _noirq variants as well.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/E1u4jMo-000rCS-6f@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>