xtensa: add build support for AMD/Phoenix #44

Job	Run time
crosstool (ubuntu-latest)	3m 9s
toolchains (ubuntu-latest, aarch64-unknown-linux-gnu)	59m 59s
toolchains (ubuntu-latest, arc-multilib-linux-uclibc)	57m 38s
toolchains (ubuntu-latest, arm-picolibc-eabi)	1h 49m 6s
toolchains (ubuntu-latest, arm-unknown-linux-gnueabi)	1h 16m 3s
toolchains (ubuntu-latest, armv6-nommu-linux-uclibcgnueabi)	53m 2s
toolchains (ubuntu-latest, mips-unknown-elf)	26m 13s
toolchains (ubuntu-latest, mips64-unknown-linux-gnu)	46m 37s
toolchains (ubuntu-latest, powerpc-unknown-linux-gnu)	56m 20s
toolchains (ubuntu-latest, powerpc64-unknown-linux-gnu)	1h 5m 5s
toolchains (ubuntu-latest, riscv32-unknown-elf)	16m 19s
toolchains (ubuntu-latest, riscv64-unknown-elf)	30m 8s
toolchains (ubuntu-latest, s390-unknown-linux-gnu)	49m 10s
toolchains (ubuntu-latest, sh-multilib-linux-gnu)	1h 54m 2s
toolchains (ubuntu-latest, sparc-unknown-linux-gnu)	47m 50s
toolchains (ubuntu-latest, x86_64-unknown-linux-gnu)	1h 0m 6s
toolchains (ubuntu-latest, x86_64-multilib-linux-uclibc)	1h 1m 3s
toolchains (ubuntu-latest, xtensa-fsf-linux-uclibc)	43m 13s
	16h 15m 3s

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