configs/linux/skiroot_p9_defconfig: Add CONFIG_I40E=m and CONFIG_IGB=m

These modules are used by hardware shipped with SuperMicro p9dsu systems,
and Supermicro has enabled these in their builds for testing purposes
for quite a few months and things seem to be going smoothly there.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
diff --git a/openpower/configs/linux/skiroot_p9_defconfig b/openpower/configs/linux/skiroot_p9_defconfig
index 1130b8e..9b5c8ae 100644
--- a/openpower/configs/linux/skiroot_p9_defconfig
+++ b/openpower/configs/linux/skiroot_p9_defconfig
@@ -131,6 +131,8 @@
 CONFIG_E1000E=m
 CONFIG_IXGB=m
 CONFIG_IXGBE=m
+CONFIG_I40E=m
+CONFIG_IGB=m
 CONFIG_MLX4_EN=m
 CONFIG_MLX5_CORE=m
 CONFIG_MLX5_CORE_EN=y