S390: Add new hwcap values for new cpu architecture arch13.

S390: Add new hwcap values for new cpu architecture arch13.

The new hwcap values indicate support for:
-"Vector-Enhancements Facility 2" (tag "vxe2", hwcap 2^15)
-"Vector-Packed-Decimal-Enhancement Facility" (tag "vxp", hwcap 2^16)
-"Enhanced-Sort Facility" (tag "sort", hwcap 2^17)
-"Deflate-Conversion Facility" (tag "dflt", hwcap 2^18)

The vxe2 hwcap is also marked as important hwcap.

ChangeLog:

	* sysdeps/s390/dl-procinfo.c (_dl_s390_cap_flags):
	Add vxe2, vxp, dflt, sort flags.
	* sysdeps/s390/dl-procinfo.h: Add HWCAP_S390_VXRS_EXT2,
	HWCAP_S390_VXRS_PDE, HWCAP_S390_SORT, HWCAP_S390_DFLT
	capabilities.
	(HWCAP_IMPORTANT): Add HWCAP_S390_VXRS_EXT2.
	* sysdeps/unix/sysv/linux/s390/bits/hwcap.h
	(HWCAP_S390_VXRS_EXT2, HWCAP_S390_VXRS_PDE, HWCAP_S390_SORT,
	HWCAP_S390_DFLT): Define.