Add trace tag for power management.

#define ATRACE_TAG_DALVIK           (1<<14)

#define ATRACE_TAG_RS               (1<<15)

#define ATRACE_TAG_BIONIC           (1<<16)

#define ATRACE_TAG_LAST             ATRACE_TAG_BIONIC

#define ATRACE_TAG_POWER            (1<<17)

#define ATRACE_TAG_LAST             ATRACE_TAG_POWER

// Reserved for initialization.

#define ATRACE_TAG_NOT_READY        (1LL<<63)