drivers/ddr/fsl: Fix DDR4 RDIMM support

drivers/ddr/fsl: Fix DDR4 RDIMM support

For DDR4, command/address delay in mode registers and parity latency
in timing config register are only needed for UDIMMs, but not RDIMMs.
Add additional register rcw_3 for DDR4 RDIMM. Fix mirrored bit for
dual rank RDIMMs. Set sdram_cfg_3[DIS_MRS_PAR] for RDIMMs. Fix
calculation of timing config registers. Use hexadecimal format for
printing RCW (register control word) registers.

Signed-off-by: York Sun <york.sun@nxp.com>