esdhc: Add CONFIG_SYS_FSL_ESDHC_LE and CONFIG_SYS_FSL_ESDHC_BE macros

For LS102xA, the processor is in little-endian mode, while esdhc IP is
in big-endian mode. CONFIG_SYS_FSL_ESDHC_LE and CONFIG_SYS_FSL_ESDHC_BE
are added. So accessing ESDHC registers can be determined by ESDHC IP's
endian mode.

Signed-off-by: Alison Wang <alison.wang@freescale.com>