sched/clock: independent the CLOCK_BOOTTIME

The previous commit will cause build break if the definition of clock
id is used in the switch case.

Change-Id: Iecd078818d28879883dd582b236372ba43171b13
Signed-off-by: chao.an <anchao@xiaomi.com>

include/time.h

@@ -93,7 +93,7 @@
 /* Monotonic system-wide clock that includes time spent in suspension. */
 
 #ifdef CONFIG_CLOCK_MONOTONIC
-#  define CLOCK_BOOTTIME CLOCK_MONOTONIC
+#  define CLOCK_BOOTTIME   2
 #endif
 
 /* This is a flag that may be passed to the timer_settime() and

sched/clock/clock_getres.c

@@ -74,6 +74,7 @@ int clock_getres(clockid_t clock_id, struct timespec *res)
 
 #ifdef CONFIG_CLOCK_MONOTONIC
       case CLOCK_MONOTONIC:
+      case CLOCK_BOOTTIME:
 #endif
       case CLOCK_REALTIME:
 

sched/clock/clock_gettime.c

@@ -88,7 +88,7 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
    * is invoked with a clock_id argument of CLOCK_MONOTONIC."
    */
 
-  if (clock_id == CLOCK_MONOTONIC)
+  if (clock_id == CLOCK_MONOTONIC || clock_id == CLOCK_BOOTTIME)
     {
       /* The the time elapsed since the timer was initialized at power on
        * reset.

sched/timer/timer_create.c

@@ -161,6 +161,7 @@ int timer_create(clockid_t clockid, FAR struct sigevent *evp,
   if (timerid == NULL || (clockid != CLOCK_REALTIME
 #ifdef CONFIG_CLOCK_MONOTONIC
       && clockid != CLOCK_MONOTONIC
+      && clockid != CLOCK_BOOTTIME
 #endif /* CONFIG_CLOCK_MONOTONIC */
       ))
     {