sh: Fix FDPIC binary loader

Ensure that the aux table is properly initialized, even when optional features
are missing.  Without this, the FDPIC loader did not work.  This was meant to
be included in commit d5ab7803.

Signed-off-by: Thomas Schwinge <thomas@codesourcery.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>