dm: spi: Correct BIOS protection logic for ICH9

The logic is incorrect and currently has no effect. Fix it so that we can
write to SPI flash, since by default it is write-protected.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Andrew Bradford <andrew.bradford@kodakalaris.com>

drivers/spi/ich.c

@@ -40,6 +40,7 @@ struct ich_spi_priv {
 	int status;
 	int control;
 	int bbar;
+	int bcr;
 	uint32_t *pr;		/* only for ich9 */
 	int speed;		/* pointer to speed control */
 	ulong max_speed;	/* Maximum bus speed in MHz */
@@ -239,6 +240,7 @@ static int ich_init_controller(struct ich_spi_platdata *plat,
 		ctlr->speed = ctlr->control + 2;
 		ctlr->bbar = offsetof(struct ich9_spi_regs, bbar);
 		ctlr->preop = offsetof(struct ich9_spi_regs, preop);
+		ctlr->bcr = offsetof(struct ich9_spi_regs, bcr);
 		ctlr->pr = &ich9_spi->pr[0];
 		ctlr->base = ich9_spi;
 	} else {
@@ -688,13 +690,10 @@ static int ich_spi_probe(struct udevice *bus)
 	 * v9, deassert SMM BIOS Write Protect Disable.
 	 */
 	if (plat->use_sbase) {
-		struct ich9_spi_regs *ich9_spi;
-
-		ich9_spi = priv->base;
-		bios_cntl = ich_readb(priv, ich9_spi->bcr);
+		bios_cntl = ich_readb(priv, priv->bcr);
 		bios_cntl &= ~(1 << 5);	/* clear Enable InSMM_STS (EISS) */
 		bios_cntl |= 1;		/* Write Protect Disable (WPD) */
-		ich_writeb(priv, bios_cntl, ich9_spi->bcr);
+		ich_writeb(priv, bios_cntl, priv->bcr);
 	} else {
 		pci_read_config_byte(plat->dev, 0xdc, &bios_cntl);
 		if (plat->ich_version == 9)