This patch adds CONFIG_SPL_NAND_DEVICE_WIDTH to specify bus-width of NAND device
CONFIG_SPL_NAND_DEVICE_WIDTH == 16: NAND device with x16 bus-width
CONFIG_SPL_NAND_DEVICE_WIDTH == 8: NAND device with x8 bus-width
Need for a separate CONFIG_xx arise from following situations.
(1) SPL NAND drivers does not have framework to parse ONFI parameter page.
(2) if !defined(CONFIG_SYS_NAND_SELF_INIT)
|- board_nand_init()
|- nand_scan()
|- nand_scan_ident()
|- nand_scan_tail()
This means board_nand_init() is called before nand_scan_ident(). So NAND
controller is initialized before the actual probing of NAND device.
However some controller (like GPMC) need to be specifically configured for
bus-width of NAND device.
In such cases, bus-width of the NAND device should be known in advance
of actual device probing. Hence, CONFIG_SPL_NAND_DEVICE_WIDTH is useful.
(3) Non-ONFI compliant devices need some mechanism to specify device bus-width
to driver.
Signed-off-by: Pekon Gupta <pekon@ti.com>