bus: add sigbus handler

bus: add sigbus handler

When a device is hot-unplugged, a sigbus error will occur of the datapath
can still read/write to the device. A handler is required here to capture
the sigbus signal and handle it appropriately.

This patch introduces a bus ops to handle sigbus errors. Each bus can
implement its own case-dependent logic to handle the sigbus errors.

Signed-off-by: Jeff Guo <jia.guo@intel.com>
Acked-by: Shaopeng He <shaopeng.he@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>