Remove binaries/usr/lib/libbfd-2.21.1.so and /usr/bin/nm from the repo.
Instead use the compiled versions in buildroot.

Patch the installation rule to install only "nm", when
PACKAGE_BINUTILS_TARGET is not used(!).
libbfd-2.21.1.so is installed by default by the installation rule of
PACKAGE_BINUTILS.

Binary nm was added in the commit:
d2a486cc rootfs_override: add /usr/bin/nm and its libbfd
Signed-off-by: Adam Wujek <adam.wujek@cern.ch>