cpu_arm: Support all ARM processors we know about

So far three ARM processor families are known to libvirt,
however the cpu driver knows only about one of them. This
make host initialization on the other two fail:

2014-06-17 13:35:41.419+0000: 6840: info : libvirt version: 1.2.6
2014-06-17 13:35:41.419+0000: 6840: error : cpuNodeData:342 : this function is not supported by the connection driver: cannot get node CPU data for armv6l architecture
2014-06-17 13:35:41.433+0000: 6840: warning : virQEMUCapsInit:943 : Failed to get host CPU
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/cpu/cpu_arm.c

@@ -30,7 +30,9 @@
 
 #define VIR_FROM_THIS VIR_FROM_CPU
 
-static const virArch archs[] = { VIR_ARCH_ARMV7L };
+static const virArch archs[] = {VIR_ARCH_ARMV6L,
+                                VIR_ARCH_ARMV7B,
+                                VIR_ARCH_ARMV7L};
 
 static virCPUDataPtr
 ArmNodeData(virArch arch)