drivers/spi/spi_flash: add flash region protection to controller

Provide a spi controller specific protection callback to take
advantage of special spi flash controllers that have internal
protection registers built into the implementation. It's an
optional callback for spi controllers.

BUG=b:69614064

Change-Id: Ie50a6ce3bbda32620a25dd26fda1af944940bf28
Signed-off-by: Aaron Durbn <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/22879
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/drivers/spi/spi_flash.c

@@ -459,3 +459,29 @@ void lb_spi_flash(struct lb_header *header)
 		flash->erase_cmd = CMD_BLOCK_ERASE;
 	}
 }
+
+
+int spi_flash_ctrlr_protect_region(const struct spi_flash *flash,
+					const struct region *region)
+{
+	const struct spi_ctrlr *ctrlr;
+	struct region flash_region = { 0 };
+
+	if (!flash)
+		return -1;
+
+	flash_region.size = flash->size;
+
+	if (!region_is_subregion(&flash_region, region))
+		return -1;
+
+	ctrlr = flash->spi.ctrlr;
+
+	if (!ctrlr)
+		return -1;
+
+	if (ctrlr->flash_protect)
+		return ctrlr->flash_protect(flash, region);
+
+	return -1;
+}