mtd: nand: zynq: Add a config option to use 1st stage bootloader timing

mtd: nand: zynq: Add a config option to use 1st stage bootloader timing

In legacy method, 1st stage bootloader was used to configure the HW
setting such as NAND timing. Hence, adding a config option in Zynq
NAND driver for the compatibility of device that using 1st stage
bootloder instead of U-boot SPL.

This commit is to add config option
CONFIG_NAND_ZYNQ_USE_BOOTLOADER1_TIMINGS that allow NAND driver use
timing values set by the 1st stage bootloader, instead of the hard-coded
values in the Zynq NAND driver.

Signed-off-by: Jeff Westfahl <jeff.westfahl@ni.com>
Signed-off-by: Wilson Lee <wilson.lee@ni.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Keng Soon Cheah <keng.soon.cheah@ni.com>
Cc: Chen Yee Chew <chen.yee.chew@ni.com>
Cc: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Scott Wood <oss@buserror.net>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>