flasher: Use flash via MTD device

Now that we have a kernel driver for the NOR, switch do doing all
operations via the MTD device.

Change-Id: Iff760b79f0779665b44d9118643486900ea8946c
Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/op-flasher/flasher_obj.c b/op-flasher/flasher_obj.c
index 3b92c82..747ad0b 100644
--- a/op-flasher/flasher_obj.c
+++ b/op-flasher/flasher_obj.c
@@ -181,7 +181,7 @@
 	int rc;
 	printf("Setting up BMC flash\n");
 
-	if(arch_flash_bmc(bl, BMC_DIRECT) != BMC_DIRECT) {
+	if(arch_flash_bmc(bl, BMC_MTD) != BMC_MTD) {
 		fprintf(stderr, "Failed to init flash chip\n");
 		return FLASH_SETUP_ERROR;
 	}