package/elfutils: fix build with uclibc

package/elfutils: fix build with uclibc

Update first patch to fix a build failure with uclibc and elfutils in
version 0.183.0 which errors out if obstack is not found since
https://sourceware.org/git/?p=elfutils.git;a=commit;h=da855fc9cd415c288bfcb9de1f3d5eb329de0557

Indeed, obstack has been removed from uclibc-ng since version 1.0.21 and
https://github.com/wbx-github/uclibc-ng/commit/0bd6bfb2b643ea2b4b1440dfd917ba752f0c0d15

Fixes:
 - http://autobuild.buildroot.org/results/003ae73c7b48ad6b9837fb19ca197061d20eaf6d

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Reviewed-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>