Yakkety update to v4.8.15 stable release

SRU Justification

    Impact:
       The upstream process for stable tree updates is quite similar
       in scope to the Ubuntu SRU process, e.g., each patch has to
       demonstrably fix a bug, and each patch is vetted by upstream
       by originating either directly from a mainline/stable Linux tree or
       a minimally backported form of that patch. The v4.8.15 upstream stable
       patch set is now available. It should be included in the Ubuntu
       kernel as well.

       git://git.kernel.org/

    TEST CASE: TBD

       The following patches from the v4.8.15 stable release shall be applied:

powerpc/eeh: Fix deadlock when PE frozen state can't be cleared
powerpc/mm: Fix lazy icache flush on pre-POWER5
powerpc/boot: Fix build failure in 32-bit boot wrapper
fuse: fix clearing suid, sgid for chown()
parisc: Purge TLB before setting PTE
parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_page_asm
parisc: Fix TLB related boot crash on SMP machines
zram: restrict add/remove attributes to root only
locking/rtmutex: Prevent dequeue vs. unlock race
locking/rtmutex: Use READ_ONCE() in rt_mutex_owner()
device-dax: fix private mapping restriction, permit read-only
sched/autogroup: Fix 64-bit kernel nice level adjustment
vhost-vsock: fix orphan connection reset
perf/x86: Fix full width counter, counter overflow
acpi, nfit: fix extended status translations for ACPI DSMs
acpi, nfit, libnvdimm: fix / harden ars_status output length handling
acpi, nfit: validate ars_status output buffer size
acpi, nfit: fix bus vs dimm confusion in xlat_status
crypto: marvell - Don't copy hash operation twice into the SRAM
crypto: caam - fix pointer size for AArch64 boot loader, AArch32 kernel
crypto: mcryptd - Check mcryptd algorithm compatibility
crypto: marvell - Don't corrupt state of an STD req for re-stepped ahash
can: raw: raw_setsockopt: limit number of can_filter that can be set
can: peak: fix bad memory access and free sequence
Revert "ACPI: Execute _PTS before system reboot"
ARM: dts: orion5x: fix number of sata port for linkstation ls-gl
ARM: dts: imx7d: fix LCDIF clock assignment
ceph: don't set req->r_locked_dir in ceph_d_revalidate
m68k: Fix ndelay() macro
batman-adv: Check for alloc errors when preparing TT local data
hotplug: Make register and unregister notifier API symmetric
crypto: rsa - Add Makefile dependencies to fix parallel builds
Linux 4.8.15