intel/compiler: Stop including src/mesa/main/config.h

src/mesa/main includes are for Mesa's OpenGL implementation, and the
compiler is used in Vulkan drivers and other tools.  We really only
needed one #define, which is that we offer 32 samplers.  It probably
makes more sense to have our own defined limit for that rather than
importing a project-wide value which theoretically could be adjusted,
so swap MAX_SAMPLERS for a new BRW_MAX_SAMPLERS and call it a day.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17309>

src/intel/compiler/brw_debug_recompile.c

@@ -73,7 +73,7 @@ debug_sampler_recompile(const struct brw_compiler *c, void *log,
    found |= check("ayuv image bound", ayuv_image_mask);
    found |= check("xyuv image bound", xyuv_image_mask);
 
-   for (unsigned i = 0; i < MAX_SAMPLERS; i++) {
+   for (unsigned i = 0; i < BRW_MAX_SAMPLERS; i++) {
       found |= check("EXT_texture_swizzle or DEPTH_TEXTURE_MODE", swizzles[i]);
       found |= check("textureGather workarounds", gfx6_gather_wa[i]);
       found |= check_float("scale factor", scale_factors[i]);