ANDROID: cpufreq_interactive: Add missing includes

Cpufreq interfaces have been moved to <linux/sched/cpufreq.h>,
see upstream commit 7284c6d4 ("sched/headers: Move the
cpufreq interfaces to <linux/sched/cpufreq.h>") for reference.

Similarly upstream commit cda66725 ("sched/headers: Move the
get_task_struct()/put_task_struct() and related APIs from
<linux/sched.h> to <linux/sched/task.h>", moved [get,put]_task_struct()
APIs as well.

Also drop <linux/sched.h> which is no longer required, upstream
commit ed53742d ("sched/headers: Remove <linux/sched.h>
from <linux/sched/cpufreq.h>").

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>