mtd: spi-nor: micron: Add SPI_NOR_DUAL_READ flag on mt25qu02g

The Micron mt25qu02g supports both x2 and x4 transactions. Add the
SPI_NOR_DUAL_READ flag to its spi_nor_ids[] table entry.

Tested on Pensando SoC hardware with a cadence quadspi controller
via drivers/spi/spi-cadence-quadspi.c, in x2 mode at 50MHz.
  - random data write, erase, read   - verified erase operations
  - random data write, read/compare  - verified write/read operations
Signed-off-by: David Clear <dac2@pensando.io>
Acked-by: Shannon Nelson <snelson@pensando.io>
Link: https://lore.kernel.org/r/20200720163656.38006-3-dac2@pensando.ioSigned-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

drivers/mtd/spi-nor/micron-st.c

@@ -71,8 +71,8 @@ static const struct flash_info st_parts[] = {
 			      SECT_4K | USE_FSR | SPI_NOR_QUAD_READ |
 			      NO_CHIP_ERASE) },
 	{ "mt25qu02g",   INFO(0x20bb22, 0, 64 * 1024, 4096,
-			      SECT_4K | USE_FSR | SPI_NOR_QUAD_READ |
-			      NO_CHIP_ERASE) },
+			      SECT_4K | USE_FSR | SPI_NOR_DUAL_READ |
+			      SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
 
 	{ "m25p05",  INFO(0x202010,  0,  32 * 1024,   2, 0) },
 	{ "m25p10",  INFO(0x202011,  0,  32 * 1024,   4, 0) },