kernel: Make kmod-nft-core depend on kmod-nf-nat

In kernel 5.4 kmod-nf-core depends on kmod-nf-nat, add this missing
dependency.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

package/kernel/linux/modules/netfilter.mk

@@ -1049,7 +1049,7 @@ $(eval $(call KernelPackage,ipt-rpfilter))
 define KernelPackage/nft-core
   SUBMENU:=$(NF_MENU)
   TITLE:=Netfilter nf_tables support
-  DEPENDS:=+kmod-nfnetlink +kmod-nf-reject +kmod-nf-reject6 +kmod-nf-conntrack6
+  DEPENDS:=+kmod-nfnetlink +kmod-nf-reject +kmod-nf-reject6 +kmod-nf-conntrack6 +LINUX_5_4:kmod-nf-nat
   FILES:=$(foreach mod,$(NFT_CORE-m),$(LINUX_DIR)/net/$(mod).ko)
   AUTOLOAD:=$(call AutoProbe,$(notdir $(NFT_CORE-m)))
   KCONFIG:= \