Drop the following patches:
* the Xtensa patches 870 and 871 are upstream now
* patch 942 was backported to GCC 6 branch
Note, that a bz2 release tarball is not provided anymore and is replaced by
a xz tarball file.
Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
