packagegroup-core-sdk.bb: Drop distcc from the core-sdk.
distcc has been used in the past to speed up native compile across
several machines. This is less an issue on modern embedded systems.
Also, improvements in sdk generation have reduced the need for on target
compile of large projects.
Since the distcc packages start a daemon at boot, drop it from the
packagegroup to avoid having some slight runtime impact on systems
installing an sdk.
Signed-off-by: Philip Balister <philip@balister.org> Signed-off-by: Ross Burton <ross.burton@intel.com>
