zephyr: shell: Fix implicit declaration of function 'strtol'

Fix implicit declaration of function 'strtol' by including
stdlib.h.

Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

Author: Jyri Sarha

zephyr/sof_shell.c

@@ -12,6 +12,8 @@
 #include <zephyr/sys/printk.h>
 #include <zephyr/shell/shell.h>
 
+#include <stdlib.h>
+
 #define SOF_TEST_INJECT_SCHED_GAP_USEC 1500
 
 static int cmd_sof_test_inject_sched_gap(const struct shell *sh,