coreutils-native: don't install groups

coreutils-native: don't install groups

This binary is provided by shadow-native nowadays. Fixes:

  ERROR: The recipe coreutils-native is trying to install files \
    into a shared area when those files already exist. \
    Those files and their manifest location are: \
      .../tmp/sysroots/x86_64-linux/usr/bin/groups \
    Matched in manifest-x86_64-shadow-native.populate_sysroot

To reproduce the errors:

  $ bitbake shadow-native && bitbake coreutils-native

Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>