programmer: import upstream get_buses_supported() fn

V.2: rebase on master.

BUG=chromium:478356
BRANCH=none
TEST=still builds

Change-Id: I100224deefcbbd48f2207ebfdab2c9cface809d6
Signed-off-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/1731354
Reviewed-by: Sam McNally <sammc@chromium.org>
diff --git a/programmer.c b/programmer.c
index 1af52b0..a4841db 100644
--- a/programmer.c
+++ b/programmer.c
@@ -12,7 +12,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
  */
 
 #include "flash.h"
@@ -147,3 +146,13 @@
 	{ NULL },
 };
 struct programmer_alias *alias;
+enum chipbustype get_buses_supported(void)
+{
+	int i;
+	enum chipbustype ret = BUS_NONE;
+
+	for (i = 0; i < registered_master_count; i++)
+		ret |= registered_masters[i].buses_supported;
+
+	return ret;
+}