Merge tag 'mtk-mtd-spi-move' into spi-nor/next

spi: Rewrite mtk-quadspi spi-nor driver with spi-mem

This patchset from Chuanhong Guo <[email protected]> adds a spi-mem
driver for Mediatek SPI-NOR controller, which already has limited
support by mtk-quadspi. This new driver can make use of full quadspi
capability of this controller.

The mtk-quadspi driver is replaced by the new spi-mtk-nor driver.
Merge it in spi-nor/next to avoid conflicts during the release cycle.