linux-obmc: Unifiy defconfigs

Minimaise the differences between the ast2400 and ast2500 defconifgs.

ast2500 changes:
 - Enable IPv6
 - Disable unused compression algorithms
 - Enable SYN cookies
   * resolves https://github.com/openbmc/openbmc/issues/504
 - Enable kenrel hardening features
 - Disable unused USB support
 - Enable earlyprintk
 - Disable support for ancient libc

ast2400 changes:
 - Remove unused configfs support
 - Disable IPv6 IPSec support

Change-Id: Id1e388723160541de80b26c378b87a1a2da8091e
Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/meta-ast2400/recipes-kernel/linux/linux-obmc/defconfig b/meta-ast2400/recipes-kernel/linux/linux-obmc/defconfig
index fbfc3c7..b6cdb94 100644
--- a/meta-ast2400/recipes-kernel/linux/linux-obmc/defconfig
+++ b/meta-ast2400/recipes-kernel/linux/linux-obmc/defconfig
@@ -51,6 +51,10 @@
 # CONFIG_INET_XFRM_MODE_TUNNEL is not set
 # CONFIG_INET_XFRM_MODE_BEET is not set
 # CONFIG_INET_DIAG is not set
+# CONFIG_INET6_XFRM_MODE_TRANSPORT is not set
+# CONFIG_INET6_XFRM_MODE_TUNNEL is not set
+# CONFIG_INET6_XFRM_MODE_BEET is not set
+# CONFIG_IPV6_SIT is not set
 CONFIG_NETFILTER=y
 CONFIG_IP_NF_IPTABLES=y
 CONFIG_IP_NF_FILTER=y
@@ -146,7 +150,6 @@
 CONFIG_VFAT_FS=y
 CONFIG_TMPFS=y
 CONFIG_TMPFS_POSIX_ACL=y
-CONFIG_CONFIGFS_FS=y
 CONFIG_JFFS2_FS=y
 CONFIG_JFFS2_SUMMARY=y
 CONFIG_JFFS2_FS_XATTR=y