sched: micro optimization for sched_energy_present

sched_energy_present is always present for chipsets that are supported,
so, switch to static_branch_likely() to let compiler know the same for
better optimization.

Change-Id: Ie4615ae6f7d1ec7498d0708f500c5a5a72ef4b4d
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>