etnaviv: expose ARB_seamless_cube_map

While AMD_seamless_cubemap_per_texture gives more control over seamless
filtering than the base extension, the cap isn't strictly handled as a
superset, so we also need to set the cap for the context wide handling
to expose ARB_seamless_cube_map.

Makes piglit spec@amd_seamless_cubemap_per_texture go from skip to pass
as this test (correctly) also checks the presence of the base extension.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35527>

docs/features.txt

@@ -90,7 +90,7 @@ GL 3.2, GLSL 1.50 --- all DONE: freedreno, nv50, nvc0, r600, radeonsi, llvmpipe,
   GL_ARB_draw_elements_base_vertex (Base vertex offset) DONE (v3d, vc4, panfrost, lima, crocus)
   GL_ARB_fragment_coord_conventions (Frag shader coord) DONE (v3d, vc4, panfrost, lima, crocus)
   GL_ARB_provoking_vertex (Provoking vertex)            DONE (v3d, vc4, panfrost, lima, crocus)
-  GL_ARB_seamless_cube_map (Seamless cubemaps)          DONE (panfrost, crocus)
+  GL_ARB_seamless_cube_map (Seamless cubemaps)          DONE (panfrost, crocus, etnaviv/SEAMLESS_CUBE_MAP)
   GL_ARB_texture_multisample (Multisample textures)     DONE (freedreno/a5xx+, v3d, vc4, panfrost)
   GL_ARB_depth_clamp (Frag depth clamp)                 DONE (panfrost, crocus, v3d/vc7+)
   GL_ARB_sync (Fence objects)                           DONE (v3d, vc4, panfrost, lima, crocus)

src/gallium/drivers/etnaviv/etnaviv_screen.c

@@ -277,6 +277,7 @@ etna_init_screen_caps(struct etna_screen *screen)
 
    caps->min_texel_offset = -8;
    caps->max_texel_offset = 7;
+   caps->seamless_cube_map = screen->specs.seamless_cube_map;
    caps->seamless_cube_map_per_texture = screen->specs.seamless_cube_map;
 
    /* Render targets. */