Add kconfig options for various SPI flashes and use them in cm-fx6 defconfig.
Cc: Jagan Teki <jteki@openedev.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>