powerpc/configs: Remove old symbols from defconfigs

Update defconfigs to remove old symbols and comments referencing old
symbols.

Dropped:

* AVERAGE
* INET_LRO
* EXT3_DEFAULTS_TO_ORDERED
* EXT3_FS_XATTR
* I2O
* INFINIBAND_AMSO1100
* INFINIBAND_EHCA
* IP1000

Replaced:

* BLK_DEV_XIP -> BLK_DEV_RAM_DAX
* CLK_PPC_CORENET -> CLK_QORIQ
* EXT2_FS_XIP -> FS_DAX
* EXT3_FS* -> EXT4_FS*

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/configs/mpc866_ads_defconfig b/arch/powerpc/configs/mpc866_ads_defconfig
index 321412c..9984544 100644
--- a/arch/powerpc/configs/mpc866_ads_defconfig
+++ b/arch/powerpc/configs/mpc866_ads_defconfig
@@ -24,7 +24,6 @@
 CONFIG_IP_MULTICAST=y
 CONFIG_IP_PNP=y
 CONFIG_SYN_COOKIES=y
-# CONFIG_INET_LRO is not set
 # CONFIG_IPV6 is not set
 CONFIG_BLK_DEV_LOOP=y
 CONFIG_NETDEVICES=y
@@ -37,8 +36,7 @@
 CONFIG_GEN_RTC=y
 CONFIG_EXT2_FS=y
 CONFIG_EXT2_FS_XATTR=y
-CONFIG_EXT3_FS=y
-# CONFIG_EXT3_DEFAULTS_TO_ORDERED is not set
+CONFIG_EXT4_FS=y
 CONFIG_TMPFS=y
 CONFIG_CRAMFS=y
 CONFIG_NFS_FS=y