powerpc/t4240: updated rcw_cfg to align with default hardware configuration

Default configuration has been changed, the most important one is DDR
ref_clock which is changed from 66.67MHz to 133.33MHz. so the ratio need to
change from 24x to 12x to keep the DDR frequency. There are also some
other optimise to align with default configuration.

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
1 file changed