timer: Use a shorter error in TPL

This error should not happen in normal use. Reduce the length of it to
save space in the image.

Add an empty spl.h file to sh since it appears to lack this.

Signed-off-by: Simon Glass <sjg@chromium.org>

lib/time.c

@@ -9,6 +9,7 @@
 #include <dm.h>
 #include <errno.h>
 #include <init.h>
+#include <spl.h>
 #include <time.h>
 #include <timer.h>
 #include <watchdog.h>
@@ -96,8 +97,13 @@ uint64_t notrace get_ticks(void)
 	}
 
 	ret = timer_get_count(gd->timer, &count);
-	if (ret)
-		panic("Could not read count from timer (err %d)\n", ret);
+	if (ret) {
+		if (spl_phase() > PHASE_TPL)
+			panic("Could not read count from timer (err %d)\n",
+			      ret);
+		else
+			panic("no timer (err %d)\n", ret);
+	}
 
 	return count;
 }