Move ocf_request from utils

ocf_request has always been first class citizen in OCF,
so lets place it along with another essential objects.

Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

src/mngt/ocf_mngt_common.c

@@ -9,7 +9,7 @@
 #include "../ocf_ctx_priv.h"
 #include "../metadata/metadata.h"
 #include "../engine/cache_engine.h"
-#include "../utils/utils_req.h"
+#include "../ocf_request.h"
 #include "../utils/utils_device.h"
 #include "../eviction/ops.h"
 #include "../ocf_logger_priv.h"