gallium: add PIPE_CAP_GRAPHICS

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>

src/gallium/auxiliary/util/u_screen.c

@@ -43,6 +43,7 @@ u_pipe_screen_get_param_defaults(struct pipe_screen *pscreen,
    case PIPE_CAP_POINT_SPRITE:
       return 0;
 
+   case PIPE_CAP_GRAPHICS:
    case PIPE_CAP_MAX_RENDER_TARGETS:
       return 1;
 

src/gallium/docs/source/screen.rst

@@ -22,6 +22,8 @@ or integer values, use :ref:`get_param`.
 
 The integer capabilities:
 
+* ``PIPE_CAP_GRAPHICS``: Whether graphics is supported. If not, contexts can
+  only be created with PIPE_CONTEXT_COMPUTE_ONLY.
 * ``PIPE_CAP_NPOT_TEXTURES``: Whether :term:`NPOT` textures may have repeat modes,
   normalized coordinates, and mipmaps.
 * ``PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS``: How many dual-source blend RTs are support.

src/gallium/include/pipe/p_defines.h

@@ -685,6 +685,7 @@ enum pipe_conservative_raster_mode
  */
 enum pipe_cap
 {
+   PIPE_CAP_GRAPHICS,
    PIPE_CAP_NPOT_TEXTURES,
    PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS,
    PIPE_CAP_ANISOTROPIC_FILTER,