It's possible for a native recipe to have virtual/libiconv-native as a build
dependency, but as we expect that the host provides that add it to
ASSUME_PROVIDED.
(From OE-Core rev: a5e6f5939c0ee4280eabd7cfc01131052040bc81)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>