The cpu_do_idle() function is always used by the cpuidle drivers.

That led to have each driver including cpuidle.h and proc-fns.h, they are
always paired. That makes a lot of duplicate headers inclusion. Instead of
including both in each .c file, move the proc-fns.h header inclusion in the
cpuidle.h header file directly, so we can save some line of code.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NKevin Hilman <khilman@linaro.org>
Acked-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>