patchelf: Fix alignment patch

The previous fix was in the right direction but needed to account
for the section alignment of the current section. Tweak the patch
to handle this.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit e464efc0)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>