kernel: bump 4.9 to 4.9.116

Refreshed all patches

Remove upstreamed patches.
- 103-MIPS-ath79-fix-register-address-in-ath79_ddr_wb_flus.patch
- 403-mtd_fix_cfi_cmdset_0002_status_check.patch
- 001-4.11-01-mtd-m25p80-consider-max-message-size-in-m25p80_read.patch
- 001-4.15-08-bcm63xx_enet-correct-clock-usage.patch
- 001-4.15-09-bcm63xx_enet-do-not-write-to-random-DMA-channel-on-B.patch
- 900-gen_stats-fix-netlink-stats-padding.patch

Introduce a new backported patch to address ext4 breakage, introduced in 4.9.112
- backport-4.9/500-ext4-fix-check-to-prevent-initializing-reserved-inod.patch

This patch has been slightly altered to compensate for a new helper function
introduced in later kernels.

Also add ARM64_SSBD symbol to ARM64 targets still running kernel 4.9

Compile-tested on: ar71xx, bcm2710
Runtime-tested on: ar71xx

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>

target/linux/generic/hack-4.9/220-gc_sections.patch

@@ -33,9 +33,9 @@ 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)
-@@ -636,11 +641,6 @@ KBUILD_CFLAGS	+= $(call cc-disable-warni
- KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
+@@ -637,11 +642,6 @@ KBUILD_CFLAGS	+= $(call cc-disable-warni
  KBUILD_CFLAGS	+= $(call cc-disable-warning, int-in-bool-context)
+ KBUILD_CFLAGS	+= $(call cc-disable-warning, attribute-alias)
  
 -ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 -KBUILD_CFLAGS	+= $(call cc-option,-ffunction-sections,)