Fixed removal of z_impl_clock_gettime in zephyr 3.5.99 (#378)

* Fixed removal of z_impl_clock_gettime in zephyr 3.5.99

Signed-off-by: Daniel Huiskes <d.v.huiskes@student.utwente.nl>

* crustify z_impl_clock_gettime fix

* single return  z_impl_clock_gettime fix

---------

Signed-off-by: Daniel Huiskes <d.v.huiskes@student.utwente.nl>
Co-authored-by: Daniel Huiskes <d.v.huiskes@student.utwente.nl>

Author: danielallstar

src/c/util/time.c

@@ -7,6 +7,8 @@
 #elif defined(UCLIENT_PLATFORM_FREERTOS_PLUS_TCP)
 #include "FreeRTOS.h"
 #include "task.h"
+#elif defined(UCLIENT_PLATFORM_ZEPHYR)
+#include <version.h>
 #endif /* ifdef WIN32 */
 
 //==================================================================
@@ -53,7 +55,16 @@ int64_t uxr_nanos(
     return (( total_tick / (int64_t) portTICK_PERIOD_MS ) * 1000000 );
 #elif defined(UCLIENT_PLATFORM_ZEPHYR)
     struct timespec ts;
+
+    // From Zephyr version 3.5.99 the z_impl_clock_gettime function
+    // has been renamed to the clock_gettime function.
+    // This has been done to implement Zephyr's POSIX API as regular library functions
+    // https://github.com/zephyrproject-rtos/zephyr/commit/95a22b12174621aeba8ca3e0e61f7c66f03202bf
+    #if ZEPHYR_VERSION_CODE >= ZEPHYR_VERSION(3, 5, 99)
+    clock_gettime(CLOCK_REALTIME, &ts);
+    #else
     z_impl_clock_gettime(CLOCK_REALTIME, &ts);
+    #endif /* if ZEPHYR_VERSION_CODE >= ZEPHYR_VERSION(3, 5, 99) */
     return (((int64_t)ts.tv_sec) * 1000000000) + ts.tv_nsec;
 #else
     struct timespec ts;