Merge tag 'spi-nor/for-4.20' of git://git.infradead.org/linux-mtd into mtd/next

Core changes:
* Support non-uniform erase size
* Support controllers with limited TX fifo size

Driver changes:
* m25p80: Re-issue a WREN command after each write access
* cadence: Pass a proper dir value to dma_[un]map_single()
* fsl-qspi: Check fsl_qspi_get_seqid() return val make sure 4B
  addressing opcodes are properly handled
* intel-spi: Add a new PCI entry for Ice Lake