arm64: defconfig: Enable ENETC Ethernet controller and FELIX switch

Enables drivers for NXP ENETC Ethernet controller and FELIX Ethernet
switch used on QorIQ LS1028a SoC.

The ENETC ethernet drivers are enabled as built-in to boot from network
without an initramfs.

Signed-off-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>