driver/ddr/fsl: Add workaround for erratum A-009803

During initial DDR training, false parity errors may be detected.
This patch adds workaround to fix the erratum.
Tested on LS2085QDS and LS2080RDB.

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