$ ./config.sub powerpc-eabivle
Invalid configuration `powerpc-eabivle': OS `eabivle' not recognized
$ ./config.sub powerpc-unknown-eabivle
Invalid configuration `powerpc-unknown-eabivle': OS `eabivle' not recognized

Also powerpc-eabisim and probably some arm configurations.

	* config.sub: Accept OS of eabi* and gnueabi*.