Fix invalid principled diffuse in Cycles OSL

Need to initialize components for the full Diffuse BSDF.

Steps to reproduce:
- Default cube scene
- Switch to Cycles renderer
- Enable OSL backend
- Start viewport render
- Observe cube being much black

Differential Revision: https://developer.blender.org/D12921

intern/cycles/kernel/closure/bsdf_principled_diffuse.h

@@ -49,6 +49,7 @@ static_assert(sizeof(ShaderClosure) >= sizeof(PrincipledDiffuseBsdf),
 ccl_device int bsdf_principled_diffuse_setup(ccl_private PrincipledDiffuseBsdf *bsdf)
 {
   bsdf->type = CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID;
+  bsdf->components = PRINCIPLED_DIFFUSE_FULL;
   return SD_BSDF | SD_BSDF_HAS_EVAL;
 }