[libc] Split time clock from pthreads

components/libc/Kconfig

@@ -52,6 +52,10 @@ if RT_USING_LIBC && RT_USING_DFS
     config RT_USING_POSIX_AIO
         bool "Enable AIO"
         default n
+
+    config RT_USING_POSIX_CLOCKTIME
+        bool "Enable POSIX clock_time APIs"
+        default n
     endif
 
 endif

components/libc/time/SConscript

@@ -6,10 +6,7 @@ cwd = GetCurrentDir()
 src = Glob('*.c') + Glob('*.cpp')
 CPPPATH = [cwd]
 
-#group = DefineGroup('pthreads', src, 
-#    depend = ['RT_USING_PTHREADS'], CPPPATH = CPPPATH)
-
 group = DefineGroup('pthreads', src, 
-    depend = [''], CPPPATH = CPPPATH)
+    depend = ['RT_USING_POSIX_CLOCKTIME'], CPPPATH = CPPPATH)
 
 Return('group')

components/lwp/Kconfig

@@ -2,6 +2,7 @@ config RT_USING_LWP
     bool "Using light-weight process"
     select RT_USING_DFS
     select RT_USING_LIBC
+    select RT_USING_POSIX_CLOCKTIME
     depends on ARCH_ARM_CORTEX_M || ARCH_ARM_ARM9 || ARCH_ARM_CORTEX_A
     default n
     help