Add secondary CPUs processor frequency for e500 core

This patch updates e500 freqProcessor to array based on CONFIG_NUM_CPUS,
and prints each CPU's frequency separately. It also fixes up each CPU's
frequency in "clock-frequency" of fdt blob.

Signed-off-by: James Yang <James.Yang@freescale.com>
Signed-off-by: Haiying Wang <Haiying.Wang@freescale.com>