Add variant console passphrase needle for i386

For quite a while on i386 the 'enter passphrase' console screen
has used bright white text, for some reason. Let's just have a
variant needle for this instead of worrying too hard about why.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

needles/console/boot_enter_passphrase-blackwhite-20180507.json

@@ -0,0 +1,15 @@
+{
+  "properties": [],
+  "area": [
+    {
+      "width": 185,
+      "type": "match",
+      "ypos": 15,
+      "xpos": 0,
+      "height": 17
+    }
+  ],
+  "tags": [
+    "boot_enter_passphrase"
+  ]
+}