plat: imx8mq: fix boot hang on ddr4/ddr3l board

Currently, DDR3L/DDR4 board don't support DDR DVFS,
So skip ddr switch 3200 mts if the DDR is not LPDDR4.

Signed-off-by: Bai Ping <ping.bai@nxp.com>
(cherry picked from commit 02cba32824185a28605130e7a7ae6dd79f3e4fa6)
1 file changed