KVM: x86: Fold irq_comm.c into irq.c
Drop irq_comm.c, a.k.a. common IRQ APIs, as there has been no non-x86 user
since commit 003f7de62589 ("KVM: ia64: remove") (at the time, irq_comm.c
lived in virt/kvm, not arch/x86/kvm).
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20250611213557.294358-19-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>