KVM: x86: Merge 'svm' into 'cet' to pick up GHCB dependencies

Merge the queue of SVM changes for 6.18 to pick up the KVM-defined GHCB
helpers so that kvm_ghcb_get_xss() can be used to virtualize CET for
SEV-ES+ guests.

diff --cc arch/x86/include/asm/cpufeatures.h
Simple merge

diff --cc arch/x86/include/asm/kvm_host.h
Simple merge

diff --cc arch/x86/kvm/svm/svm.c
Simple merge

diff --cc arch/x86/kvm/x86.c
Simple merge