Merge pull request #3052 from Lawlieta/develop

[net] Remove libc select in SAL and AT Socket function

components/net/Kconfig

@@ -5,7 +5,6 @@ menu "Socket abstraction layer"
 config RT_USING_SAL
     bool "Enable socket abstraction layer"
     select RT_USING_NETDEV
-    select RT_USING_LIBC
     select RT_USING_SYSTEM_WORKQUEUE
     default n
 
@@ -37,6 +36,7 @@ config RT_USING_SAL
             bool "Enable BSD socket operated by file system API"
             default n
             select RT_USING_DFS
+            select RT_USING_LIBC
             select RT_USING_POSIX
             help
                 Let BSD socket operated by file system API, such as read/write and involveed in select/poll POSIX APIs.

components/net/at/Kconfig

@@ -58,7 +58,6 @@ if RT_USING_AT
 
         config AT_USING_SOCKET
             bool "Enable BSD Socket API support by AT commnads"
-            select RT_USING_LIBC
             select RT_USING_SAL
             default n