phy: ti: phy-j721e-wiz: Add SGMII support in wiz driver for J7200

Select the same mac divider for SGMII too as the one being used for
QSGMII.

Enable full rate divider configuration support for J721E_WIZ_10G for
SGMII.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>