openjdk7: use icedtea6-native instead of icedtea7-native
openjdk7: use icedtea6-native instead of icedtea7-native

* the current icedtea7 seems to have some issues when compiling
  on recent linux distribution
* switch back to icedtea6-native to have a reliable state
  for building openjdk7

woglinde/meta-java,rdm-dev/meta-java,woglinde/meta-java,woglinde/meta-java,tobw/meta-java,rehsack/meta-java,Valtis/meta-java,tobw/meta-java,rehsack/meta-java,Valtis/meta-java,rdm-dev/meta-java,Valtis/meta-java,rehsack/meta-java,rehsack/meta-java,rdm-dev/meta-java,rehsack/meta-java,tobw/meta-java,sunlabtech/meta-java