Change in coreboot[master]: payloads: Add UefiPayload support to ARM64 platforms

[Hung-Te Lin (Code Review)]

Attention is currently required from: Martin Roth, Rex-BC Chen, Paul Menzel, Julius Werner, Marty E. Plummer.
Hung-Te Lin has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/58054 )

Change subject: payloads: Add UefiPayload support to ARM64 platforms
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Patch Set 6:

(1 comment)

Patchset:

PS6: 
I verified with the following step:

1. make menuconfig
2. select Mainboard -> Vendor=Google, model=Cherry
3. select Payload -> Add a payload -> Tianocore
4. make -j
5. build/cbfstool  build/coreboot.rom extract --name fallback/payload --file out.elf -m arm64
6. file out.elf # ELF 64-bit LSB executable, ARM aarch64
7. strings out.elf | grep tianocore # lots of tianocore stuff

Can't verify if the tianocore boots, but at least it can compile without problems.