openrisc: Change toolchain from or32- to or1k-

The openrisc toolchain prefix changed a few years ago.  No one
should be using this anylonger. This also saves from people
having to manually update or specify this every build.
Signed-off-by: Stafford Horne <shorne@gmail.com>

arch/openrisc/configs/or1ksim_defconfig

-CONFIG_CROSS_COMPILE="or32-linux-"
+CONFIG_CROSS_COMPILE="or1k-linux-"
 CONFIG_NO_HZ=y
 CONFIG_LOG_BUF_SHIFT=14
 CONFIG_BLK_DEV_INITRD=y