x86/cpu/topology: Check for X86_FEATURE_XTOPOLOGY instead of passing has_xtopology

cpu_parse_topology_ext() sets X86_FEATURE_XTOPOLOGY before returning
true if any of the XTOPOLOGY leaf (0x80000026 / 0xb) could be parsed
successfully.

Instead of storing and passing around this return value using
"has_xtopology" in parse_topology_amd(), check for X86_FEATURE_XTOPOLOGY
directly in parse_8000_001e() to simplify the flow.

No functional changes intended.

Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/20250901170418.4314-1-kprateek.nayak@amd.com