powerpc/85xx: fix a bug with the parameter of mpic_reset_core()

mpic_reset_core() need a logical cpu number instead of physical.

Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>