add NPTL for cortex-m CPU's

target/config/Config.in.cpu

@@ -180,6 +180,7 @@ config ADK_TARGET_CPU_ARM_CORTEX_A57
 
 config ADK_TARGET_CPU_ARM_CORTEX_M7
 	bool "cortex-m7"
+	select ADK_TARGET_SUPPORTS_NPTL
 	select ADK_TARGET_SUPPORTS_THREADS
 	select ADK_TARGET_SUPPORTS_LT
 	select ADK_TARGET_CPU_WITH_THUMB2
@@ -188,6 +189,7 @@ config ADK_TARGET_CPU_ARM_CORTEX_M7
 
 config ADK_TARGET_CPU_ARM_CORTEX_M4
 	bool "cortex-m4"
+	select ADK_TARGET_SUPPORTS_NPTL
 	select ADK_TARGET_SUPPORTS_THREADS
 	select ADK_TARGET_SUPPORTS_LT
 	select ADK_TARGET_CPU_WITH_THUMB2
@@ -196,6 +198,7 @@ config ADK_TARGET_CPU_ARM_CORTEX_M4
 
 config ADK_TARGET_CPU_ARM_CORTEX_M3
 	bool "cortex-m3"
+	select ADK_TARGET_SUPPORTS_NPTL
 	select ADK_TARGET_SUPPORTS_THREADS
 	select ADK_TARGET_SUPPORTS_LT
 	select ADK_TARGET_CPU_WITH_THUMB2