kernel: generic: Add kernel 4.14 support

This adds initial support for kernel 4.14 based on the patches for
kernel 4.9.

In the configuration I deactivated some of the new possible security
features like:
CONFIG_REFCOUNT_FULL
CONFIG_SLAB_FREELIST_HARDENED
CONFIG_SOFTLOCKUP_DETECTOR
CONFIG_WARN_ALL_UNSEEDED_RANDOM

And these overlay FS options are also deactivated:
CONFIG_OVERLAY_FS_INDEX
CONFIG_OVERLAY_FS_REDIRECT_DIR

I activated this:
CONFIG_FORTIFY_SOURCE
CONFIG_POSIX_TIMERS
CONFIG_SLAB_MERGE_DEFAULT
CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED

I am not sure if I did the porting correct for the following patches:
target/linux/generic/backport-4.14/020-backport_netfilter_rtcache.patch
target/linux/generic/hack-4.14/220-gc_sections.patch
target/linux/generic/hack-4.14/321-powerpc_crtsavres_prereq.patch
target/linux/generic/pending-4.14/305-mips_module_reloc.patch
target/linux/generic/pending-4.14/611-netfilter_match_bypass_default_table.patch
target/linux/generic/pending-4.14/680-NET-skip-GRO-for-foreign-MAC-addresses.patch

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

include/kernel-version.mk

@@ -5,10 +5,12 @@ LINUX_RELEASE?=1
 LINUX_VERSION-3.18 = .71
 LINUX_VERSION-4.4 = .100
 LINUX_VERSION-4.9 = .67
+LINUX_VERSION-4.14 = .6
 
 LINUX_KERNEL_HASH-3.18.71 = 5abc9778ad44ce02ed6c8ab52ece8a21c6d20d21f6ed8a19287b4a38a50c1240
 LINUX_KERNEL_HASH-4.4.100 = 9936cd99c4bd35f6bc6962c9acdd1fa2ac8999e07a9be6a94a03b5492f1bd14f
 LINUX_KERNEL_HASH-4.9.67 = 7fbaa7dcc17877dfa0c96fb9a7d2f4ffed20ceeb13cbbeb18d77213c6cf75f7d
+LINUX_KERNEL_HASH-4.14.6 = 0907678ba9ea146ddbdecd0a0b6363f56b896b5c61c9a15e809effb3ea346ccc
 
 ifdef KERNEL_PATCHVER
   LINUX_VERSION:=$(KERNEL_PATCHVER)$(strip $(LINUX_VERSION-$(KERNEL_PATCHVER)))