This helper has been introduced to avoid programmer errors (missing
_put calls leading to dangling refcnt) when using pm_runtime_get, use it.

While at it, start checking the return value.
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Fixes: 5c829028 ("drm/msm/dsi: Split PHY drivers to separate files")
Patchwork: https://patchwork.freedesktop.org/patch/543350/
Link: https://lore.kernel.org/r/20230620-topic-dsiphy_rpm-v2-1-a11a751f34f0@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>