soc: qcom: Fix mhi_qdss mode permission issue

QDSS mhi_qdss mode node permission sometimes cannot be updated
by ueventd, this is because mode node is not created after ueventd
received qdss KOBJ_ADD event. This change solves this issue.

Change-Id: Ibdb1051db7f442fb27f6501ec81742127e0bf930
Signed-off-by: Yuanfang Zhang <zhangyuanfang@codeaurora.org>