valgrind: Update suppression file to align with updated POSIX arch

Things have moved around so we need to update the
suppression file so the callstack and types of
leaks valgrind reports still match.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>

scripts/valgrind.supp

@@ -10,20 +10,28 @@
 {
    POSIX arch no thread cleanup
    Memcheck:Leak
-   match-leak-kinds: possible
+   match-leak-kinds: reachable,possible
    ...
-   fun:pthread_create*
    fun:posix_new_thread
+   fun:arch_new_thread
 }
 {
-   POSIX arch no cpu cleanup
+   POSIX soc no cpu cleanup
    Memcheck:Leak
-   match-leak-kinds: possible
+   match-leak-kinds: reachable
    ...
-   fun:pthread_create*
    fun:posix_boot_cpu
+   ...
    fun:main
 }
+{
+   POSIX arch no cpu cleanup
+   Memcheck:Leak
+   match-leak-kinds: reachable
+   ...
+   fun:nct_init
+   fun:posix_arch_init
+}
 {
    lvgl no cleanup
    Memcheck:Leak