UPSTREAM: PM / devfreq: rk3399_dmc: Remove explictly regulator_put call in .remove

UPSTREAM: PM / devfreq: rk3399_dmc: Remove explictly regulator_put call in .remove

Current code uses devm_regulator_get() in .probe so a regulator_put() will
be automatically called when unload the module. Remove the explictly
regulator_put() call and then we can also remove rk3399_dmcfreq_remove().

Change-Id: I56a62a76f06403aff9ad0478e7701862084a90b3
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
(cherry picked from commit da4a64481b3504a6f4f07c08ff03be8f08d9638d)