power: msm8974: Build with with BOARD_VNDK_VERSION

time.h isnt included by default when vndk is enabled.

Change-Id: I7ca6ca601a8d25557bd1bb0484766121a9ae5633
diff --git a/power-8974.c b/power-8974.c
index f5b2970..3261a22 100644
--- a/power-8974.c
+++ b/power-8974.c
@@ -31,6 +31,7 @@
 #define LOG_NIDEBUG 0
 
 #include <errno.h>
+#include <time.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>