mm: include malloc.h in mm/mm.h

to remove the forward declaration of mallinfo and mallinfo_task

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

mm/kmm_heap/kmm_mallinfo.c

@@ -24,8 +24,6 @@
 
 #include <nuttx/config.h>
 
-#include <malloc.h>
-
 #include <nuttx/mm/mm.h>
 
 #ifdef CONFIG_MM_KERNEL_HEAP

mm/mm_heap/mm_mallinfo.c

@@ -24,7 +24,6 @@
 
 #include <nuttx/config.h>
 
-#include <malloc.h>
 #include <assert.h>
 #include <debug.h>
 

mm/mm_heap/mm_malloc.c

@@ -27,7 +27,6 @@
 #include <assert.h>
 #include <debug.h>
 #include <string.h>
-#include <malloc.h>
 
 #include <nuttx/arch.h>
 #include <nuttx/mm/mm.h>

mm/mm_heap/mm_memdump.c

@@ -25,7 +25,6 @@
 #include <nuttx/config.h>
 
 #include <stdio.h>
-#include <malloc.h>
 #include <assert.h>
 #include <debug.h>
 

mm/tlsf/mm_tlsf.c

@@ -29,7 +29,6 @@
 #include <assert.h>
 #include <debug.h>
 #include <execinfo.h>
-#include <malloc.h>
 #include <sched.h>
 #include <stdio.h>
 #include <string.h>