Fix: Disable KleidiAI on systems with SME1 but not SME2
This PR fixes an issue where KleidiAI was incorrectly enabled on systems that support SME1 but not SME2, leading to crashes.
The issue was reported in #26377.
The fix involves changing the check in onnxruntime/core/mlas/lib/platform.cpp to use HasArm_SME2() instead of HasArm_SME(). This ensures that KleidiAI is only enabled on systems that have SME2 support.
