msc_sm2s_imx8mp: Make Ethernet functional

Currently, the Ethernet ports are not working.

The Ethernet PHY reset lines are controlled by the TCA6424 I2C GPIO
expander.

The TCA6424 I2C GPIO expander is supported by the CONFIG_DM_PCA953X
driver.

Select the CONFIG_DM_PCA953X option so that the Ethernet PHYs can
go through a proper reset making Ethernet to be functional.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Ian Ray <ian.ray@gehealthcare.com>