mtd: nand: davinci: don't request AEMIF address range

The TI AEMIF driver registers are used to setup timings for each chip
select. The same registers range is used to setup NAND settings.
The AEMIF and NAND drivers not use the same registers in this range.

In case with TI AEMIF driver, the memory address range is requested
already by AEMIF, so we cannot request it twice, just ioremap.

Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Taras Kondratiuk <taras@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>