kernel: bump 4.19 to 4.19.16

Refresh patches.
Remove upstreamed patches:
- backport/096-mips-math-emu-Write-protect-delay-slot-emulation-pages.patch
- backport/096-v4.20-netfilter-ipv6-Preserve-link-scope-traffic-original-.patch
- backport/424-v4.20-net-dsa-fix-88e6060-roaming.patch
- hack/100-mtd-rawnand-qcom-fix-memory-corruption-that-causes-p.patch
- pending/510-f2fs-fix-sanity_check_raw_super-on-big-endian-machines.patch
Update patch that no longer applies:
- backport/343-netfilter-nft_flow_offload-handle-netdevice-events-f.patch

Compile-tested: mesongx
Runtime-tested: mesongx

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

target/linux/generic/pending-4.19/920-mangle_bootargs.patch

@@ -13,7 +13,7 @@ Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
 
 --- a/init/Kconfig
 +++ b/init/Kconfig
-@@ -1522,6 +1522,15 @@ config EMBEDDED
+@@ -1527,6 +1527,15 @@ config EMBEDDED
  	  an embedded system so certain expert options are available
  	  for configuration.