switch_voltage is required on some platform since special register accessing
Signed-off-by: NJorge A. Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: NDan Yuan <yuandan@hisilicon.com>
Signed-off-by: NZhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>