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>