[S] Change in flashrom[master]: flashrom.c: Guard against sending spi commands on non-spi mst

[Edward O'Callaghan (Code Review)]

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/71269 )

Change subject: flashrom.c: Guard against sending spi commands on non-spi mst
......................................................................

flashrom.c: Guard against sending spi commands on non-spi mst

Validate (flash->chip->bustype == BUS_SPI) as ich copies the
chip flags in the opaque master and tries incorrectly
to issue 4BA commands which results in failure.

The issue was detected only in the case of chips >16MB, in
this case 'W25Q256FV' that has the feature bits:
```
 .feature_bits   = FEATURE_WRSR_WREN | FEATURE_OTP | FEATURE_4BA_ENTER_WREN |
                   FEATURE_4BA_EAR_C5C8 | FEATURE_4BA_READ | FEATURE_4BA_FAST_READ |
                   FEATURE_WRSR2,
```
The regression was noticed from,
commit 0741727925b841c2479b993204ce58c5eb75185a ichspi.c: Read chip ID and use it to populate `flash->chip`

TEST=In the case of 'W25Q256FV' on TigerLake.

Change-Id: I7cce4f9c032d33c01bf616e27a50b9727a40fe1b
Signed-off-by: Edward O'Callaghan 
---
M flashrom.c
1 file changed, 28 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/69/71269/1

diff --git a/flashrom.c b/flashrom.c
index 62f38f8..f6862c4 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -1944,7 +1944,8 @@
    }

/* Enable/disable 4-byte addressing mode if flash chip supports it */
-	if (flash->chip->feature_bits & (FEATURE_4BA_ENTER | FEATURE_4BA_ENTER_WREN | FEATURE_4BA_ENTER_EAR7)) {
+	if ((flash->chip->bustype == BUS_SPI) &&
+	    (flash->chip->feature_bits & (FEATURE_4BA_ENTER | FEATURE_4BA_ENTER_WREN | FEATURE_4BA_ENTER_EAR7))) {
    	int ret;
    	if (spi_master_4ba(flash))
    		ret = spi_enter_4ba(flash);