uboot-imx

sunxi_nand_spl: Parametrize lowlevel read functions

Parametrize the lowlevel nand_read_page function, instead of directly
using the CONFIG_foo settings for page-size, etc. there and add a few
wrappers / helper functions for calling it.

This is a preparation patch for adding auto-detecting of the nand
parameters like the BROM does.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>