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 d5ab780305bb6d60a7b5a74f18cf84eb6ad153b1.

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