net: Convert CONFIG_IP_DEFRAG to Kconfig

Convert CONFIG_IP_DEFRAG to Kconfig, update defconfigs, headers
and whitelist. This patch is a follow-up on a patch by Christian
Gmeiner with the added config/header/whitelist updates.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Reported-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/configs/xilinx_versal_virt_defconfig b/configs/xilinx_versal_virt_defconfig
index b0b36a0..9000573 100644
--- a/configs/xilinx_versal_virt_defconfig
+++ b/configs/xilinx_versal_virt_defconfig
@@ -42,6 +42,7 @@
 # CONFIG_PARTITION_UUIDS is not set
 CONFIG_OF_BOARD=y
 CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_IP_DEFRAG=y
 CONFIG_SPL_DM_SEQ_ALIAS=y
 CONFIG_DM_GPIO=y
 CONFIG_DM_I2C=y