percpu: Use X86_MEM_ENCRYPT for decrypted per-CPU data

On Wed, Sep 16, 2026 at 01:05:39AM -0400, Zack Rusin wrote: > Decrypted per-CPU data is gated by AMD_MEM_ENCRYPT. With > INTEL_TDX_GUEST=y and AMD_MEM_ENCRYPT=n it falls back to ordinary > per-CPU sto