mtd: spi-nor-core: Allow using Micron mt35xu512aba in Octal DTR mode

Since this flash doesn't have a Profile 1.0 table, the Octal DTR
capabilities are enabled in the post SFDP fixup, along with the 8D-8D-8D
fast read settings.

Enable Octal DTR mode with 20 dummy cycles to allow running at the
maximum supported frequency of 200Mhz.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 6ece401..d68e48f 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -126,6 +126,12 @@
 /* Used for Micron flashes only. */
 #define SPINOR_OP_RD_EVCR	0x65	/* Read EVCR register */
 #define SPINOR_OP_WD_EVCR	0x61	/* Write EVCR register */
+#define SPINOR_OP_MT_DTR_RD	0xfd	/* Fast Read opcode in DTR mode */
+#define SPINOR_OP_MT_RD_ANY_REG	0x85	/* Read volatile register */
+#define SPINOR_OP_MT_WR_ANY_REG	0x81	/* Write volatile register */
+#define SPINOR_REG_MT_CFR0V	0x00	/* For setting octal DTR mode */
+#define SPINOR_REG_MT_CFR1V	0x01	/* For setting dummy cycles */
+#define SPINOR_MT_OCT_DTR	0xe7	/* Enable Octal DTR with DQS. */
 
 /* Status Register bits. */
 #define SR_WIP			BIT(0)	/* Write in progress */