gallium: remove unused first_level param from st_texture_create()

src/mesa/state_tracker/st_cb_drawpixels.c

    assert(pipeFormat);
    cpp = st_sizeof_format(pipeFormat);
 
-   pt = st_texture_create(st, PIPE_TEXTURE_2D, pipeFormat, 0, 0, width, height,
+   pt = st_texture_create(st, PIPE_TEXTURE_2D, pipeFormat, 0, width, height,
 			  1, 0);
    if (!pt)
       return NULL;
    /**
     * Create a texture.
     */
-   pt = st_texture_create(ctx->st, PIPE_TEXTURE_2D, format, 0, 0, width, height,
+   pt = st_texture_create(ctx->st, PIPE_TEXTURE_2D, format, 0, width, height,
 			  1, 0);
    if (!pt)
       return NULL;
    psRead = rbRead->surface;
    format = psRead->format;
 
-   pt = st_texture_create(ctx->st, PIPE_TEXTURE_2D, format, 0, 0, width, height,
+   pt = st_texture_create(ctx->st, PIPE_TEXTURE_2D, format, 0, width, height,
 			  1, 0);
    if (!pt)
       return;

src/mesa/state_tracker/st_cb_texture.c

    stObj->pt = st_texture_create(st,
                                  gl_target_to_pipe(stObj->base.Target),
                                  st_mesa_format_to_pipe_format(stImage->base.TexFormat->MesaFormat),
-                                 firstLevel,
                                  lastLevel,
                                  width,
                                  height,
       stObj->pt = st_texture_create(ctx->st,
                                     gl_target_to_pipe(stObj->base.Target),
                                     st_mesa_format_to_pipe_format(firstImage->base.TexFormat->MesaFormat),
-                                    0, /* first level */
                                     stObj->lastLevel,
                                     firstImage->base.Width,
                                     firstImage->base.Height,

src/mesa/state_tracker/st_texture.c

  * width0, height0, depth0 are the dimensions of the level 0 image
  * (the highest resolution).  last_level indicates how many mipmap levels
  * to allocate storage for.  For non-mipmapped textures, this will be zero.
- * XXX first_level obsolete
  */
 struct pipe_texture *
 st_texture_create(struct st_context *st,
                   enum pipe_texture_target target,
 		  enum pipe_format format,
-		  GLuint first_level,
 		  GLuint last_level,
 		  GLuint width0,
 		  GLuint height0,
 
    assert(target <= PIPE_TEXTURE_CUBE);
 
-   DBG("%s target %s format %s level %d..%d\n", __FUNCTION__,
+   DBG("%s target %s format %s last_level %d\n", __FUNCTION__,
        _mesa_lookup_enum_by_nr(target),
-       _mesa_lookup_enum_by_nr(format), first_level, last_level);
+       _mesa_lookup_enum_by_nr(format), last_level);
 
    assert(format);
 

src/mesa/state_tracker/st_texture.h

 st_texture_create(struct st_context *st,
                   enum pipe_texture_target target,
 		  enum pipe_format format,
-                  GLuint first_level,
                   GLuint last_level,
                   GLuint width0,
                   GLuint height0,