MLK-21031 arm: imx: fix standby resume hang on imx7ulp

MLK-21031 arm: imx: fix standby resume hang on imx7ulp

When system resume from VLPS mode, DDR IO must be restored
before mmdc out of the self-fresh mode.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Tested-by: Anson Huang <Anson.Huang@nxp.com>
(cherry picked from commit 7dec20bcb6633c7feee1eb32a5d81356075a61f7)
Signed-off-by: Arulpandiyan Vadivel <arulpandiyan_vadivel@mentor.com>
Signed-off-by: Shrikant Bobade <Shrikant_Bobade@mentor.com>
(cherry picked from commit 1a484976fdfda18e316c4e0b22fbbd4c99593f8d)