ARM: mvebu: Remove the unused argument of set_cpu_coherent()

set_cpu_coherent() took the SMP group ID as parameter. But this
parameter was never used, and the CPU always uses the SMP group 0. So
we can remove this parameter.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397488214-20685-5-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>