driver/ddr/fsl: Add address parity support for DDR4 UDIMM/discrete

Add support of address parity for DDR4 UDIMM or discrete memory.
It requires to configurate corresponding MR5[2:0] and
TIMING_CFG_7[PAR_LAT]. Parity can be turned on by hwconfig,
e.g. hwconfig=fsl_ddr:parity=on.

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