panfrost: Fix panfrost_small_padded_vertex_count for 17 vertices

All odd numbers above 10 need to be rounded up to an even number, so
add one and mask off the least significant bit instead of maintaining
a list of special cases.

Fixes crashes in SuperTuxKart.

Cc: mesa-stable
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8191>
(cherry picked from commit a250f3620c)

.pick_status.json

@@ -859,7 +859,7 @@
         "description": "panfrost: Fix panfrost_small_padded_vertex_count for 17 vertices",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": null
     },

src/panfrost/lib/pan_attributes.c

@@ -40,10 +40,10 @@
 static unsigned
 panfrost_small_padded_vertex_count(unsigned idx)
 {
-        if (idx == 11 || idx == 13 || idx == 15 || idx == 19)
-                return idx + 1;
-        else
+        if (idx < 10)
                 return idx;
+        else
+                return (idx + 1) & ~1;
 }
 
 static unsigned