Tested with MTA72ASS8G72PSZ-2S6G1. This is 3DS RDIMM module with x4
DDR chips. LS2088ARDB needs to be modified to connect all DQS signals.
Some of them are grounded by default for x8 chips. Tested with RDIMM
MTA18ASF2G72PDZ on main memory controllers. DP-DDR doesn't support
RDIMM. Dropped related timing table.
Signed-off-by: NYork Sun <york.sun@nxp.com>