Add kick function for cleaner

ocf_kick_cleaner() allows to perfom cleaning immediately.

Nop cleaning policy now returns new 'OCF_CLEANER_DISABLE' macro which indicates
that cleaing shouldn't be performed. To enable it back, ocf_kick_cleaner()
should be called.

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>

inc/ocf_ctx.h

@@ -145,6 +145,13 @@ struct ocf_cleaner_ops {
 	 */
 	int (*init)(ocf_cleaner_t c);
 
+	/**
+	 * @brief Kick cleaner thread.
+	 *
+	 * @param[in] c Descriptor of cleaner to be kicked.
+	 */
+	void (*kick)(ocf_cleaner_t c);
+
 	/**
 	 * @brief Stop cleaner
 	 *