ub: support query stat of ubcore device

driver inclusion
category: feature
bugzilla: NA
CVE: NA

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Add query device stat function in ubcore,
which support user in user mode to query device statistics
including tx/rx packets, running status of device.

Hw drivers should register their implementation of this api.

Signed-off-by: Guoxin Qian <qianguoxin@huawei.com>
Signed-off-by: Yizhen Fan <fanyizhen@huawei.com>