dt-bindings: nand: denali: reduce the register space in the example

This example allocates much more than needed for address regions.

As for "denali_reg", as you see in drivers/mtd/nand/denali.h, all
registers fit in 0x1000.

As for "nand_data", this IP is generally configured to use Indexed
Addressing mode, where there are only two registers in the address
translation module (CTRL: 0x00, DATA: 0x10).  Altera SOCFPGA is
also this case.  So, 0x20 is enough.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Documentation/devicetree/bindings/mtd/denali-nand.txt

@@ -29,7 +29,7 @@ nand: nand@ff900000 {
 	#address-cells = <1>;
 	#size-cells = <1>;
 	compatible = "altr,socfpga-denali-nand";
-	reg = <0xff900000 0x100000>, <0xffb80000 0x10000>;
+	reg = <0xff900000 0x20>, <0xffb80000 0x1000>;
 	reg-names = "nand_data", "denali_reg";
 	interrupts = <0 144 4>;
 };