drm/bridge: nwl-dsi: Fix PM disable depth imbalance in nwl_dsi_probe

drm/bridge: nwl-dsi: Fix PM disable depth imbalance in nwl_dsi_probe

The pm_runtime_enable will increase power disable depth.
Thus a pairing decrement is needed on the error handling
path to keep it balanced according to context.

Fixes: 3790c3fc97c0 ("drm/bridge: Add NWL MIPI DSI host controller support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220105104826.1418-1-linmq006@gmail.com
Reviewed-by: Robert Foss <robert.foss@linaro.org>