mtd: st_spi_fsm: remove SPINOR_OP_RDSR2 and use SPINOR_OP_RDCR instead

The 35h instruction op code has two aliases/macro definitions:
- SPINOR_OP_RDCR from include/linux/mtd/spi-nor.h
- SPINOR_OP_RDSR2 from drivers/mtd/devices/serial_flash_cmds.h

Actually, some manufacturers name the associated internal register Status
Register 2 whereas other manufacturers name it Configuration Register
hence the two different macros for the very same instruction op code.

Since the spi-nor.h file is the reference file for all SPI NOR instruction
op codes, this patch removes the definition of the SPINOR_OP_RDSR2 macro.

Also the SPINOR_OP_RDSR2 macro will be associated to another instruction
op code in a further patch so we need to avoid a conflict defining this
macro twice. Indeed the JESD216 rev B specification, defining the SFDP
tables, also refers to the 3Eh and 3Fh instruction op codes to write/read
the Status Register 2 on some SPI NOR flash memories, the 35h op code
still being used to read the Configuration Regi...

drivers/mtd/devices/serial_flash_cmds.h

@@ -13,7 +13,6 @@
 #define _MTD_SERIAL_FLASH_CMDS_H
 
 /* Generic Flash Commands/OPCODEs */
-#define SPINOR_OP_RDSR2		0x35
 #define SPINOR_OP_WRVCR		0x81
 #define SPINOR_OP_RDVCR		0x85
 

drivers/mtd/devices/st_spi_fsm.c

@@ -1445,7 +1445,7 @@ static int stfsm_s25fl_config(struct stfsm *fsm)
 	}
 
 	/* Check status of 'QE' bit, update if required. */
-	stfsm_read_status(fsm, SPINOR_OP_RDSR2, &cr1, 1);
+	stfsm_read_status(fsm, SPINOR_OP_RDCR, &cr1, 1);
 	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
 	if (data_pads == 4) {
 		if (!(cr1 & STFSM_S25FL_CONFIG_QE)) {
@@ -1490,7 +1490,7 @@ static int stfsm_w25q_config(struct stfsm *fsm)
 		return ret;
 
 	/* Check status of 'QE' bit, update if required. */
-	stfsm_read_status(fsm, SPINOR_OP_RDSR2, &sr2, 1);
+	stfsm_read_status(fsm, SPINOR_OP_RDCR, &sr2, 1);
 	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
 	if (data_pads == 4) {
 		if (!(sr2 & W25Q_STATUS_QE)) {