Emulate qemu-kvms -no-kvm option

Releases of qemu-kvm will be interrupted at qemu 1.3.0.
Users should switch to plain qemu releases.
To avoid breaking scenarios which are setup with command line
options specific to qemu-kvm, port these switches from qemu-kvm
to qemu.git.

Port -no-kvm option.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/vl.c b/vl.c
index cd7c0fb..b39f22e 100644
--- a/vl.c
+++ b/vl.c
@@ -3171,6 +3171,10 @@
                     machine = machine_parse(optarg);
                 }
                 break;
+             case QEMU_OPTION_no_kvm:
+                olist = qemu_find_opts("machine");
+                qemu_opts_parse(olist, "accel=tcg", 0);
+                break;
             case QEMU_OPTION_no_kvm_pit: {
                 fprintf(stderr, "Warning: KVM PIT can no longer be disabled "
                                 "separately.\n");