[rt-smart] kernel virtual memory management layer (#6809)

synchronize virtual memory system works.
adding kernel virtual memory management layer for page-based MMU enabled architecture
porting libcpu MMU codes
porting lwp memory related codes

components/mm/SConscript

@@ -0,0 +1,21 @@
+import os
+from building import *
+
+objs = []
+
+if GetDepend('ARCH_MM_MMU'):
+    cwd  = GetCurrentDir()
+    src	= Glob('*.c') + Glob('*_gcc.S')
+    CPPPATH = [cwd]
+
+    group = DefineGroup('mm', src, depend = [''], CPPPATH = CPPPATH)
+
+    objs = [group]
+    list = os.listdir(cwd)
+
+    for d in list:
+        path = os.path.join(cwd, d)
+        if os.path.isfile(os.path.join(path, 'SConscript')):
+            objs = objs + SConscript(os.path.join(d, 'SConscript'))
+
+Return('objs')