kernel: bump 4.9 to 4.9.82

Refresh patches.
Remove upstreamed patches:
- ar7/002-MIPS-AR7-ensure-the-port-type-s-FCR-value-is-used.patch
- backport/040-crypto-fix-typo-in-KPP-dependency-of-CRYPTO_ECDH.patch
Remove layerscape/819-Revert-dmaengine-dmatest-move-callback-wait-queue-to.patch,
it is superseded by upstream commit 297c7cc4b5651b174a62925b6c961085f04979fd.
Remove pending/650-pppoe_header_pad.patch, it is superseded by
upstream commit 1bd21b158e07e0b8c5a2ce832305a0ebfe42c480.
Update patches that no longer apply:
- ar71xx/004-register_gpio_driver_earlier.patch
- hack/204-module_strip.patch
- pending/493-ubi-set-ROOT_DEV-to-ubiblock-rootfs-if-unset.patch

Fixes CVE-2017-8824.

Compile-tested: ar71xx.
Runtime-tested: ar71xx.

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