[POWERPC] mv64x60: Fix FDT compatible names: mv64x60 => mv64360

Compatible names should refer to a specific version of the hardware,
without wildcards.  Change each instance of mv64x60 to mv64360, which
is the oldest version we currently support.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>