test-x86-cpuid-compat qtest produces warnings on TCG

When running under TCG, the 'test-x86-cpuid-compat' qtest produces warnings. You can see these for instance in the x64-freebsd-13-build CI job; here's an example: https://gitlab.com/qemu-project/qemu/-/jobs/5918818568

524/837 qemu:qtest+qtest-x86_64 / qtest-x86_64/test-x86-cpuid-compat              OK               7.32s   45 subtests passed
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stderr:
qemu-system-x86_64: warning: TCG doesn't support requested feature: CPUID.07H:EBX.intel-pt [bit 25]
qemu-system-x86_64: warning: TCG doesn't support requested feature: CPUID.07H:EBX.intel-pt [bit 25]
qemu-system-x86_64: warning: TCG doesn't support requested feature: CPUID.07H:EBX.intel-pt [bit 25]
qemu-system-x86_64: warning: TCG doesn't support requested feature: CPUID.07H:EBX.intel-pt [bit 25]
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We should investigate what's going on here, and suppress the warning messages (eg by making the test case not try to test things we know we don't implement).