fix(rmm): changes for Release build and logging

This patch sets default Release build LOG_LEVEL to
20 (LOG_LEVEL_NOTICE) to match TF-A code.
Function 'assert_cpu_slots_empty()' replaced
with 'check_cpu_slots_empty()' returning
boolean value

Change-Id: I544143510325636ba784e476dbb83b923013b0e2
Signed-off-by: AlexeiFedorov <Alexei.Fedorov@arm.com>
diff --git a/lib/realm/include/buffer.h b/lib/realm/include/buffer.h
index af2306e..3be166f 100644
--- a/lib/realm/include/buffer.h
+++ b/lib/realm/include/buffer.h
@@ -39,7 +39,7 @@
 
 struct granule;
 
-void assert_cpu_slots_empty(void);
+bool check_cpu_slots_empty(void);
 void *granule_map(struct granule *g, enum buffer_slot slot);
 void buffer_unmap(void *buf);
 
@@ -48,6 +48,7 @@
 		    unsigned int offset,
 		    size_t size,
 		    void *dest);
+
 bool ns_buffer_write(enum buffer_slot slot,
 		     struct granule *ns_gr,
 		     unsigned int offset,