[PATCH 8/8] powerpc: Add purgatory for kexec_file_load implementation.

This purgatory implementation comes from kexec-tools, almost unchanged. The only changes were that the sha256_regions global variable was renamed to sha_regions to match what kexec_file_load expects, and to use the sha256.c file from x86's purgatory to avoid adding yet another SHA-256

[PATCH 8/8] powerpc: Add purgatory for kexec_file_load implementation.

This purgatory implementation comes from kexec-tools, almost unchanged. The only changes were that the sha256_regions global variable was renamed to sha_regions to match what kexec_file_load expects, and to use the sha256.c file from x86's purgatory to avoid adding yet another SHA-256