[AArch64] Remove all traces of aarch64-without-fpu.xml.

The aarch64-without-fpu description is unused.

Linux requires an FPU, so the AArch64 native port always returns the
with-fpu variant:

static const struct target_desc *
aarch64_linux_read_description (struct target_ops *ops)
{
  initialize_tdesc_aarch64 ();
  return tdesc_aarch64;
}

When the target doesn't report a target description at all, we
fallback to a register set with an FPU:

aarch64_gdbarch_init ()
...
  if (!tdesc_has_registers (tdesc))
    tdesc = tdesc_aarch64;

This just removes the dead description.

Tested by building on x86_64 Fedora 17 with --enable=targets=all.

gdb/
2013-05-29  Pedro Alves  <palves@redhat.com>

	* aarch64-tdep.c: Don't include "features/aarch64-without-fpu.c".
	(_initialize_aarch64_tdep): Don't call
	initialize_tdesc_aarch64_without_fpu.
	* features/Makefile (WHICH): Remove reference to
	aarch64-without-fpu.
	* features/aarch64-without-fpu.c: Delete file.
	* regformats/aarch64-without-fpu.dat: Delete file.