intel: add intel_{alloc,free,logv,log}()

They are per-instance equivalents of icd_{alloc,free,logv,log}().  They also
require us to embed a pointer to icd_instance in intel_handle.
diff --git a/icd/intel/obj.c b/icd/intel/obj.c
index a5ffb04..a8fcd0a 100644
--- a/icd/intel/obj.c
+++ b/icd/intel/obj.c
@@ -363,7 +363,7 @@
         return NULL;
 
     memset(base, 0, obj_size);
-    intel_handle_init(&base->handle, type);
+    intel_handle_init(&base->handle, type, handle->icd);
 
     if (debug) {
         base->dbg = intel_base_dbg_create(handle,