ANDROID: GKI: add allowed list for Exynosauto SoC

THis patch adds GKI symbol list for Exynosauto SoC. We need to add
below 6 function symbols and it required
by DRM(Direct Rendering Manager) driver.

 6 function symbol(s) added
  'void display_timings_release(struct display_timings*)'
  'int drm_connector_set_path_property(struct drm_connector*, const char*)'
  'int drm_helper_connector_dpms(struct drm_connector*, int)'
  'int drm_helper_probe_detect(struct drm_connector*, struct drm_modeset_acquire_ctx*, bool)'
  'uint32_t drm_of_crtc_port_mask(struct drm_device*, struct device_node*)'
  'int videomode_from_timings(const struct display_timings*, struct videomode*, unsigned int)'
:
Bug: 423768389
Signed-off-by: Daehyun Seo <dae.seo@samsung.com>
Change-Id: Ie7081959796e680bc4bb61c89b7439e1788ed517