build: Add ARM64 architecture support This enables the ARM64 architecture support in Bazel, including: - ARM64 toolchain configuration from Zephyr SDK (v0.17.4) - ARM64 platform and core compilation overlay (including Cortex-A53 support) - Board support for qemu_cortex_a53 - Added snippets-text-sections.ld support in linker snippet generator Change-Id: I5c43d66fa4e229e42568418b3caa25840e0f2b96 Reviewed-on: https://pigweed-review.googlesource.com/c/zephyr/zephyr-bazel/+/406698