boards: arm64: Build Zephyr for Intel SoC FPGA Agilex development kit

This is the initial Zephyr support for Intel SoC FPGA Agilex support.
Agilex has quad-core 64-bit Arm Cortex*-A53.

This patch build Zephyr for Agilex development kit with 256KB SDRAM and
support hello_world sample code. The Zephyr will need to be loaded by
Intel Arm Trusted Firmware (ATF).

Agilex Zephyr boot flow:
	FSBL:ATF BL2(EL3) -> SSBL:ATF BL31(EL3) -> OS:Zephyr(EL2->EL1)

Intel ATF can be loaded from:
	https://github.com/altera-opensource/arm-trusted-firmware.git

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>
6 files changed