esdhc/usdhc: Fix PIO mode bug in fsl_esdhc driver

esdhc/usdhc: Fix PIO mode bug in fsl_esdhc driver

When configure the fsl_esdhc driver to PIO mode by defining
"CONFIG_SYS_FSL_ESDHC_USE_PIO", the SD/MMC read and write will fail.

Two bugs in the driver to cause the issue:
1. The read buffer was invalidated after reading from DATAPORT register,
which should be only applied to DMA mode. The valid data in cache was
overwritten by physical memory.
2. The watermarks are not set in PIO mode, will cause according state not
be set.

Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Ye.Li <B37916@freescale.com>