The memory power supply on MX23 didn't pump out enough juice into
the DRAM chip, thus caused occasional memory corruption. Fix this.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>