plat: imx8mq: fix boot hang if no valid dram info

If no valid dram info to copy from DRAM, skip
copy the dram info.

Signed-off-by: Bai Ping <ping.bai@nxp.com>
(cherry picked from commit bbc3e45463808a8d2f69c2fd95fe46c4078f6d2e)
1 file changed