PM / devfreq: passive: revert an editing accident in SPDX-License line

Commit 26984d9d ("PM / devfreq: passive: Keep cpufreq_policy for
possible cpus") reworked governor_passive.c, and accidently added a
tab in the first line, i.e., the SPDX-License-Identifier line.

The checkpatch script warns with the SPDX_LICENSE_TAG warning, and hence
pointed this issue out while investigating checkpatch warnings.

Revert this editing accident. No functional change.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>