mesa: Add support to _mesa_bytes_per_vertex_attrib for 10_11_11 format.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/mesa/main/glformats.c

@@ -345,6 +345,11 @@ _mesa_bytes_per_vertex_attrib(GLint comps, GLenum type)
          return sizeof(GLuint);
       else
          return -1;
+   case GL_UNSIGNED_INT_10F_11F_11F_REV:
+      if (comps == 3)
+         return sizeof(GLuint);
+      else
+         return -1;
    default:
       return -1;
    }