drm_hwcomposer: Relax failure when no EDID property is found

Crosvm doesn't implement EDID virtio cmd, so when commit
b3d81781

 ("drm_hwcomposer: Add GetDisplayCapabilities
and getDisplayIdentificationData") landed, it broke crosvm
targets using --gpu_mode=drm_virgl

This patch tries to ease that restriction, so a lack of EDID
isn't considered fatal.

Change-Id: I8ce899fc71d2b1187d364918328473ef1890d52d
Signed-off-by: John Stultz <john.stultz@linaro.org>

drm/drmconnector.cpp

@@ -60,8 +60,7 @@ int DrmConnector::Init() {
   }
   ret = drm_->GetConnectorProperty(*this, "EDID", &edid_property_);
   if (ret) {
-    ALOGE("Could not get EDID property\n");
-    return ret;
+    ALOGW("Could not get EDID property\n");
   }
   if (writeback()) {
     ret = drm_->GetConnectorProperty(*this, "WRITEBACK_PIXEL_FORMATS",