fsl_esdhc: Fix max clock frequency

The max clock of MMC is 52MHz

Signed-off-by: Jerry Huang <Changm-Ming.Huang@freescale.com>
Tested-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
1 file changed