When we set the read or write watermark in WML we should maintain the
rest of the register as is, rather than using some hard coded value.
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>