kernel: bump 4.14 to 4.14.20

Refresh patches.
Remove upstreamed patches:
- backport/080-v4.15-0001-arch-define-weak-abort.patch
- backport/081-v4.15-0002-kernel-exit.c-export-abort-to-modules.patch
Update patch that no longer applies:
pending/493-ubi-set-ROOT_DEV-to-ubiblock-rootfs-if-unset.patch

Fixes CVE-2017-8824.

Compile-tested: octeon, x86/64.
Runtime-tested: octeon, x86/64.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

target/linux/generic/hack-4.14/207-disable-modorder.patch

@@ -15,7 +15,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 
 --- a/Makefile
 +++ b/Makefile
-@@ -1212,7 +1212,6 @@ all: modules
+@@ -1213,7 +1213,6 @@ all: modules
  
  PHONY += modules
  modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
@@ -23,7 +23,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	@$(kecho) '  Building modules, stage 2.';
  	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
  
-@@ -1241,7 +1240,6 @@ _modinst_:
+@@ -1242,7 +1241,6 @@ _modinst_:
  		rm -f $(MODLIB)/build ; \
  		ln -s $(CURDIR) $(MODLIB)/build ; \
  	fi

target/linux/generic/hack-4.14/220-gc_sections.patch

@@ -33,7 +33,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  # Read KERNELRELEASE from include/config/kernel.release (if it exists)
  KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
  KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
-@@ -784,11 +789,6 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
+@@ -785,11 +790,6 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
  KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
  endif
  

target/linux/generic/hack-4.14/902-debloat_proc.patch

@@ -327,7 +327,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  
 --- a/net/core/sock.c
 +++ b/net/core/sock.c
-@@ -3383,6 +3383,8 @@ static __net_initdata struct pernet_oper
+@@ -3380,6 +3380,8 @@ static __net_initdata struct pernet_oper
  
  static int __init proto_init(void)
  {