This patch consists of the following:
1. NAND Flash Controller (NFC) pin configuration.
2. NFC clock configuration (enable the clock, initialize the clock rate.)
3. Changes to the `fsl_nfc` NFC driver:
* Code cleanup (there were compilation warnings, e.g. unused data
* `#include <asm/immap.h>` should not be used on ARM.
* Disable the GPIO configuration code on ARM.
* Use `__raw_writel/__raw_readl` instead of `out_be32/in_be32`.
The registers of the NAND Flash Controller always use the
same endianness as the MCU core.
* Make the code in fsl_nfc_get_id() and fsl_nfc_get_status()
endianness-independent (they were accessing the data from
32-bit register as an array of u8, this approach is
4. NAND support in the U-Boot configuration file.
5. Support for environment in the NAND flash in the U-Boot configuration
6. Increase the size of the `RAM` memory region to fit the statically
allocated data for the NAND driver and the U-Boot framework for NAND.