mtd: nand: spi: Add Gigadevice SPI NAND support

This patch adds support for Gigadevices SPI NAND device to the new SPI
NAND infrastructure in U-Boot. Currently only the 128MiB GD5F1GQ4UC
device is supported.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Jagan Teki <jagan@openedev.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jagan Teki <jagan@openedev.com>