net: stmmac: rk: use device rather than platform device in rk_priv_data

net: stmmac: rk: use device rather than platform device in rk_priv_data

All the code in dwmac-rk uses &bsp_priv->pdev->dev, nothing uses
bsp_priv->pdev directly. Store the struct device rather than the
struct platform_device in struct rk_priv_data, and simplifying the
code.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/E1uR6se-004Ktz-Dx@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>