etnaviv: Mark etna_rs_gen_clear_surface(..) private

There are no users outside of etnaviv_rs.c.

Signed-off-by: Christian Gmeiner <cgmeiner@igalia.com>
Tested-by: Marek Vasut <marex@denx.de>
Acked-by: David Heidelberg <david.heidelberg@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26096>

src/gallium/drivers/etnaviv/etnaviv_clear_blit.h

@@ -30,14 +30,9 @@
 #include <stdint.h>
 
 struct etna_context;
-struct etna_surface;
 
 #include "pipe/p_context.h"
 
-void
-etna_rs_gen_clear_surface(struct etna_context *ctx, struct etna_surface *surf,
-                          uint64_t clear_value);
-
 void
 etna_copy_resource(struct pipe_context *pctx, struct pipe_resource *dst,
                    struct pipe_resource *src, int first_level, int last_level);

src/gallium/drivers/etnaviv/etnaviv_rs.c

@@ -280,7 +280,7 @@ etna_submit_rs_state(struct etna_context *ctx,
 }
 
 /* Generate clear command for a surface (non-fast clear case) */
-void
+static void
 etna_rs_gen_clear_surface(struct etna_context *ctx, struct etna_surface *surf,
                           uint64_t clear_value)
 {