package/binutils: fix assertion failure in xtensa ld

xtensa ld fails with the following message

  ld: BFD (GNU Binutils) 2.31.1 internal error, aborting at
  elf32-xtensa.c:3283 in elf_xtensa_finish_dynamic_sections

during domoticz package build. It happens because of mismatch between
the size allocated for dynamic relocations in the executable image and
the number of PLT relocations actually written to the image. The
mismatch is caused by the fact that undefined weak symbol is treated as
dynamic (and thus needing PLT relocation), but xtensa linker not
expecting that.

Fixes: http://autobuild.buildroot.net/results/7885705f1b1c0f31cf21b464150f5509929c1906/


Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Backported from: e15a8da9c71336b06cb5f2706c3f6b7e6ddd95a3
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>