mtd: spi-nor: Fix whole chip erasing for stacked chips.

Currently it is possible to disable chip erase for spi-nor driver.
Some modern stacked (multi die) flash chips do not support chip
erase opcode at all but spi-nor framework needs to cope with them too.
This commit extends existing functionality to allow disable
chip erase for a single flash chip.

Signed-off-by: Marcin Krzeminski <mar.krzeminski@gmail.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>

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

@@ -85,6 +85,7 @@ struct flash_info {
 					 * Use dedicated 4byte address op codes
 					 * to support memory size above 128Mib.
 					 */
+#define NO_CHIP_ERASE		BIT(12) /* Chip does not support chip erase */
 };
 
 #define JEDEC_MFR(info)	((info)->id[0])
@@ -1631,6 +1632,8 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
 		nor->flags |= SNOR_F_USE_FSR;
 	if (info->flags & SPI_NOR_HAS_TB)
 		nor->flags |= SNOR_F_HAS_SR_TB;
+	if (info->flags & NO_CHIP_ERASE)
+		nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
 
 #ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
 	/* prefer "small sector" erase if possible */