stack: remove unneeded atomic header include

In stack module, remove the header file rte_atomic.h
as it is not being used.

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

app/test/test_stack.c

@@ -4,7 +4,6 @@
 
 #include <string.h>
 
-#include <rte_atomic.h>
 #include <rte_lcore.h>
 #include <rte_malloc.h>
 #include <rte_random.h>

lib/stack/rte_stack.c

@@ -6,7 +6,6 @@
 #include <sys/queue.h>
 
 #include <rte_string_fns.h>
-#include <rte_atomic.h>
 #include <rte_eal.h>
 #include <rte_eal_memconfig.h>
 #include <rte_errno.h>

lib/stack/rte_stack.h

@@ -19,7 +19,6 @@
 extern "C" {
 #endif
 
-#include <rte_atomic.h>
 #include <rte_compat.h>
 #include <rte_debug.h>
 #include <rte_errno.h>