net: remove dependency on posix for iso c time() function

The ISO C function time() should not depend on POSIX and this was
corrected recently via the common libc time() implementation.

Remove this dependency from the network subsystem where it has
been unduly needed for some time.

Similarly, XSI_SINGLE_PROCESS was a dependency for time() via
picolibc, because the time() implementation in picolibc relies
on the POSIX gettimeofday() call.

However, since Zephyr's common libc time() implementation no longer
depends on that, it can be removed as a dependency in the network
subsystem as well.

Signed-off-by: Chris Friedt <[email protected]>

Author: cfriedt

subsys/net/lib/config/Kconfig

@@ -206,7 +206,7 @@ endif # NET_DHCPV6
 
 config NET_CONFIG_CLOCK_SNTP_INIT
 	bool "Initialize system clock using SNTP on application startup"
-	depends on SNTP && POSIX_TIMERS
+	depends on SNTP
 	help
 	  Perform an SNTP request over networking to get and absolute
 	  wall clock time, and initialize system time from it, so

subsys/net/lib/config/init_clock_sntp.c

@@ -12,7 +12,6 @@ LOG_MODULE_DECLARE(net_config, CONFIG_NET_CONFIG_LOG_LEVEL);
 #include <zephyr/net/net_if.h>
 #include <zephyr/net/net_mgmt.h>
 #include <zephyr/net/sntp.h>
-#include <zephyr/posix/time.h>
 
 #ifdef CONFIG_NET_CONFIG_SNTP_INIT_RESYNC
 static void sntp_resync_handler(struct k_work *work);
@@ -60,7 +59,7 @@ int net_init_clock_via_sntp(void)
 
 	tspec.tv_sec = ts.seconds;
 	tspec.tv_nsec = ((uint64_t)ts.fraction * (1000 * 1000 * 1000)) >> 32;
-	res = clock_settime(CLOCK_REALTIME, &tspec);
+	res = k_clock_settime(K_CLOCK_REALTIME, &tspec);
 
 end:
 #ifdef CONFIG_NET_CONFIG_SNTP_INIT_RESYNC

subsys/net/lib/lwm2m/Kconfig

@@ -227,7 +227,7 @@ config LWM2M_RD_CLIENT_MAX_RETRIES
 config LWM2M_RESOURCE_DATA_CACHE_SUPPORT
 	bool "Resource Time series data cache support"
 	depends on (LWM2M_RW_SENML_JSON_SUPPORT || LWM2M_RW_SENML_CBOR_SUPPORT)
-	depends on (XSI_SINGLE_PROCESS && RING_BUFFER)
+	depends on RING_BUFFER
 	help
 	  Enable time series data storage.
 	  Requires time() to provide current Unix timestamp.