hwf-x86: add "intel-vaes-vpclmul" HW feature

* configure.ac (HAVE_GCC_INLINE_ASM_VAES_VPCLMUL): New.
* src/g10lib.h (HWF_INTEL_VAES_VPCLMUL): New.
* src/hwf-x86.c (detect_x86_gnuc): Check for VAES and VPCLMUL.
* src/hwfeatures.c (hwflist): Add "intel-vaes-vpclmul".

Detect support for VAES and VPCLMUL instruction sets, which allow
use of AES and PCLMUL instruction with 256-bit and 512-bit vector
registers.

• Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>