[U-Boot] [PATCH] mpc83xx: spd_sdram.c: Disable memory controllerbefore initializing

[Liu Dave-R63238]

> The memory controller could already be enabled, when spd_sdram() is
> called. This could be the case for example, when the SDRAM is 
> initialized
> by the JTAG debugger.
> 
> Signed-off-by: Stefan Roese <sr at denx.de>
> Cc: Reinhard Arlt <reinhard.arlt at esd.eu>
> Cc: Kim Phillips <kim.phillips at freescale.com>

Acked-by: Dave Liu <daveliu at freescale.com>