Prepare migration to Kconfig.
CONFIG_SYS_MAX_FLASH_BANKS_DETECT becomes boolean and
CONFIG_SYS_MAX_FLASH_BANKS define the MAX size, also used
for detection when CONFIG_SYS_MAX_FLASH_BANKS_DETECT=y
(CFI_MAX_FLASH_BANKS = CONFIG_SYS_MAX_FLASH_BANKS).
CONFIG_SYS_MAX_FLASH_BANKS become mandatory when
CONFIG_SYS_MAX_FLASH_BANKS_DETECT is activated.
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Stefan Roese <sr@denx.de>