net: stmmac: cores: remove many xxx_SHIFT definitions

net: stmmac: cores: remove many xxx_SHIFT definitions

We have many xxx_SHIFT definitions along side their corresponding
xxx_MASK definitions for the various cores. Manually using the
shift and mask can be error prone, as shown with the dwmac4 RXFSTS
fix patch.

Convert sites that use xxx_SHIFT and xxx_MASK directly to use
FIELD_GET(), FIELD_PREP(), and u32_replace_bits() as appropriate.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vdtw8-00000002Gtu-0Hyu@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>