configs: j7200_evm_a72: Enable configs for SGMII support with MAIN CPSW0

The MAIN CPSW0 instance of CPSW Ethernet Switch on TI's J7200 SoC
supports SGMII mode. To enable support for utilizing the SGMII
daughtercard with TI's DP83869 PHY, enable the corresponding config.

Also, since the SGMII daughtercard is connected to the I2C GPIO
Expander 2 connector on the J7200 EVM, powering on the Ethernet PHY and
resetting it requires GPIO Hogging capability. Enable it as well.

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