PowerPC : Make 'qemu-system-ppc64' the default emulator on ppc64[le].

PowerPC : Explicitly associate 'qemu-system-ppc64' as the
 default emulator for all 64-bit PowerPC guests ( both Big & Little Endian )
Signed-off-by: NPrerna Saxena <prerna@linux.vnet.ibm.com>

src/qemu/qemu_capabilities.c

@@ -673,9 +673,14 @@ virQEMUCapsFindBinaryForArch(virArch hostarch,
                              virArch guestarch)
 {
     char *ret;
-    const char *archstr = virQEMUCapsArchToString(guestarch);
+    const char *archstr;
     char *binary;
 
+    if (ARCH_IS_PPC64(guestarch))
+        archstr = virQEMUCapsArchToString(VIR_ARCH_PPC64);
+    else
+        archstr = virQEMUCapsArchToString(guestarch);
+
     if (virAsprintf(&binary, "qemu-system-%s", archstr) < 0)
         return NULL;