[POWERPC] Change ppc64_defconfig to use AUTOFS_V4 not V3

Defconfig ppc64 kernels running under late-model distros
may hang in the automounter rc.d script, which seems to be
expecting autofs version 4. This patch uses the newer autofs.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/configs/ppc64_defconfig

@@ -1386,8 +1386,8 @@ CONFIG_INOTIFY=y
 CONFIG_INOTIFY_USER=y
 # CONFIG_QUOTA is not set
 CONFIG_DNOTIFY=y
-CONFIG_AUTOFS_FS=y
-# CONFIG_AUTOFS4_FS is not set
+# CONFIG_AUTOFS_FS is not set
+CONFIG_AUTOFS4_FS=m
 # CONFIG_FUSE_FS is not set
 
 #