time: SCTime additions -- neq, initializer

Issue: 5818

This commit adds an initializer for the SCTime_t type and a comparison
macro for "not equal".

Use them as follows:
    SCTime_t my_var = SCTIME_INITIALIZER;
    if (SCTIME_CMP_NEQ(sctime1_val, sctime2_val)) {
    }

src/util-time.h

@@ -47,6 +47,12 @@ typedef struct {
         (t).secs = 0;                                                                              \
         (t).usecs = 0;                                                                             \
     }
+
+#define SCTIME_INITIALIZER                                                                         \
+    (SCTime_t)                                                                                     \
+    {                                                                                              \
+        .secs = 0, .usecs = 0                                                                      \
+    }
 #define SCTIME_USECS(t)          ((uint64_t)(t).usecs)
 #define SCTIME_SECS(t)           ((uint64_t)(t).secs)
 #define SCTIME_MSECS(t)          (SCTIME_SECS(t) * 1000 + SCTIME_USECS(t) / 1000)
@@ -83,6 +89,7 @@ typedef struct {
 #define SCTIME_CMP_GT(a, b)  SCTIME_CMP((a), (b), >)
 #define SCTIME_CMP_LT(a, b)  SCTIME_CMP((a), (b), <)
 #define SCTIME_CMP_LTE(a, b) SCTIME_CMP((a), (b), <=)
+#define SCTIME_CMP_NEQ(a, b) SCTIME_CMP((a), (b), !=)
 
 void TimeInit(void);
 void TimeDeinit(void);