Rename kfree to kmm_free for consistency with other naming conventions

arch/rgmp/src/bridge.c

@@ -125,7 +125,7 @@ int rtos_bridge_init(struct rgmp_bridge *b)
 	return 0;
 
 err1:
-	kfree(bridge);
+	kmm_free(bridge);
 err0:
 	return -1;
 }

arch/rgmp/src/nuttx.c

@@ -210,7 +210,7 @@ void up_release_stack(struct tcb_s *dtcb, uint8_t ttype)
       /* Use the kernel allocator if this is a kernel thread */
 
       if (ttype == TCB_FLAG_TTYPE_KERNEL) {
-          kfree(dtcb->stack_alloc_ptr);
+          kmm_free(dtcb->stack_alloc_ptr);
       } else
 #endif
       {

arch/rgmp/src/rgmp.c

@@ -85,7 +85,7 @@ void *rtos_kmalloc(int size)
 
 void rtos_kfree(void *addr)
 {
-	kfree(addr);
+	kmm_free(addr);
 }
 
 /**

arch/rgmp/src/x86/com.c

@@ -202,7 +202,7 @@ static uart_dev_t *up_alloc_com(unsigned int base, int irq)
     return dev;
 
  err1:
-    kfree(priv);
+    kmm_free(priv);
  err0:
     return NULL;
 }
@@ -213,8 +213,8 @@ static uart_dev_t *up_alloc_com(unsigned int base, int irq)
 
 static inline void up_free_com(uart_dev_t *com)
 {
-    kfree(com->priv);
-    kfree(com);
+    kmm_free(com->priv);
+    kmm_free(com);
 }
 
 /****************************************************************************