FMC2 IP supports up to 4 chip select. On MP1 SoC, only 2 of them are
available when on MP25 SoC, the 4 chip select are available.
Let's use a platform data structure for parameters that will differ.
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>