S390: Use hwcap instead of dl_hwcap in ifunc-resolvers.

S390: Use hwcap instead of dl_hwcap in ifunc-resolvers.

The renaming of hwcap arguments in ifunc-resolvers is needed
in order to prepare for further commits which refactors
ifunc handling for memset, memcmp, and memcpy.  Now you are able
to use s390_libc_ifunc_init which stores the stfle bits
within the expression for an ifunc-resolver generated by
s390_libc_ifunc_expr.

ChangeLog:

	* sysdeps/s390/multiarch/ifunc-resolve.h
	(s390_libc_ifunc_init, s390_libc_ifunc,
	s390_vx_libc_ifunc2_redirected): Use hwcap instead of dl_hwcap.