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/mediatek/patches-4.14/0048-net-core-add-RPS-balancer.patch

@@ -10,7 +10,7 @@ Signed-off-by: John Crispin <john@phrozen.org>
 
 --- a/net/core/dev.c
 +++ b/net/core/dev.c
-@@ -3551,6 +3551,58 @@ set_rps_cpu(struct net_device *dev, stru
+@@ -3621,6 +3621,58 @@ set_rps_cpu(struct net_device *dev, stru
  	return rflow;
  }
  
@@ -69,7 +69,7 @@ Signed-off-by: John Crispin <john@phrozen.org>
  /*
   * get_rps_cpu is called from netif_receive_skb and returns the target
   * CPU from the RPS map of the receiving queue for a given skb.
-@@ -3640,7 +3692,7 @@ static int get_rps_cpu(struct net_device
+@@ -3710,7 +3762,7 @@ static int get_rps_cpu(struct net_device
  try_rps:
  
  	if (map) {
@@ -78,7 +78,7 @@ Signed-off-by: John Crispin <john@phrozen.org>
  		if (cpu_online(tcpu)) {
  			cpu = tcpu;
  			goto done;
-@@ -8431,6 +8483,9 @@ static int __init net_dev_init(void)
+@@ -8795,6 +8847,9 @@ static int __init net_dev_init(void)
  		sd->backlog.weight = weight_p;
  	}