Add AArch64 HWCAP_DCPOP from Linux 4.14

[Szabolcs Nagy]

On 15/11/17 22:59, Joseph Myers wrote:
> This patch adds the HWCAP_DCPOP macro from Linux 4.14 to the AArch64
> bits/hwcap.h.
> 
> Tested (compilation only) for aarch64 with build-many-glibcs.py.
> 
> 2017-11-15  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* sysdeps/unix/sysv/linux/aarch64/bits/hwcap.h (HWCAP_DCPOP): New
> 	macro.

OK.