PM / devfreq: rk3399_dmc: Avoid static (reused) profile

This static struct can get reused if the device gets removed/reprobed,
and that causes use-after-free in its ->freq_table.

Let's just move the struct to our dynamic allocation.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>