Rather than continue to add per platform defaults, make the default a
likely common core count. 8 is also the default for x86.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>