fsl_esdhc: Fix the voltage validation process

The current code use all the voltage range support by the host
controller to do the validation.  This will cause problem when
the host supports Low Voltage Range.  Change the validation
voltage to be based on board setup.

Signed-off-by: Li Yang <leoli@freescale.com>
Tested-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>