posix: move time functions to their own module

Makefile.dep

@@ -434,6 +434,10 @@ ifneq (,$(filter posix_semaphore,$(USEMODULE)))
   USEMODULE += xtimer
 endif
 
+ifneq (,$(filter posix_time,$(USEMODULE)))
+  USEMODULE += xtimer
+endif
+
 ifneq (,$(filter lwip_sixlowpan,$(USEMODULE)))
   USEMODULE += lwip_ipv6_autoconfig
 endif

examples/posix_sockets/Makefile

@@ -22,6 +22,7 @@ USEMODULE += gnrc_ipv6_default
 USEMODULE += gnrc_udp
 USEMODULE += gnrc_sock_udp
 USEMODULE += posix_sockets
+USEMODULE += posix_time
 # Add also the shell, some shell commands
 USEMODULE += shell
 USEMODULE += shell_commands

sys/Makefile

@@ -7,6 +7,9 @@ endif
 ifneq (,$(filter posix_sockets,$(USEMODULE)))
   DIRS += posix/sockets
 endif
+ifneq (,$(filter posix_time,$(USEMODULE)))
+  DIRS += posix/time
+endif
 ifneq (,$(filter pthread,$(USEMODULE)))
   DIRS += posix/pthread
 endif

sys/posix/time/Makefile

+MODULE = posix_time
+
+include $(RIOTBASE)/Makefile.base

tests/posix_sleep/Makefile → tests/posix_time/Makefile

-APPLICATION = posix_sleep
+APPLICATION = posix_time
 include ../Makefile.tests_common
 
-USEMODULE += posix
+USEMODULE += posix_time
 
 include $(RIOTBASE)/Makefile.include