drm/msm/dsi: Remove use of device_node in dsi_host_parse_dt()

drm/msm/dsi: Remove use of device_node in dsi_host_parse_dt()

Clang warns:

  drivers/gpu/drm/msm/dsi/dsi_host.c:1903:14: error: variable 'device_node' is uninitialized when used here [-Werror,-Wuninitialized]
          of_node_put(device_node);
                      ^~~~~~~~~~~
  drivers/gpu/drm/msm/dsi/dsi_host.c:1870:44: note: initialize the variable 'device_node' to silence this warning
          struct device_node *endpoint, *device_node;
                                                    ^
                                                    = NULL
  1 error generated.

device_node's assignment was removed but not all of its uses. Remove the
call to of_node_put() and the variable declaration to clean up the
warning.

Fixes: 36246dd50225 ("drm/msm/dsi: switch to DRM_PANEL_BRIDGE")
Link: https://github.com/ClangBuiltLinux/linux/issues/1700
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/500182/
Link: https://lore.kernel.org/r/20220829165450.217628-1-nathan@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>