svga: specify 4-byte aligned vertex elements

We haven't found a case where this is needed, but it would be prudent
for some hosts, per Jose.

Reviewed-by: José Fonseca <jfonseca@vmware.com>

src/gallium/drivers/svga/svga_screen.c

@@ -238,8 +238,9 @@ svga_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_GLSL_FEATURE_LEVEL:
    case PIPE_CAP_VERTEX_BUFFER_OFFSET_4BYTE_ALIGNED_ONLY:
    case PIPE_CAP_VERTEX_BUFFER_STRIDE_4BYTE_ALIGNED_ONLY:
-   case PIPE_CAP_VERTEX_ELEMENT_SRC_OFFSET_4BYTE_ALIGNED_ONLY:
       return 0;
+   case PIPE_CAP_VERTEX_ELEMENT_SRC_OFFSET_4BYTE_ALIGNED_ONLY:
+      return 1;
 
    default:
       debug_printf("Unexpected PIPE_CAP_ query %u\n", param);