dmadev: add flag for error handling support

dmadev: add flag for error handling support

Due to HW or driver limitations, not all dmadevs may support full error
handling e.g. safely managing and reporting an invalid address to a copy
operation. The skeleton dmadev, for example, being pure software will
always seg-fault if passed an invalid address. To indicate the
availability of safe error handling by a device, we add a capability
flag for it.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Conor Walsh <conor.walsh@intel.com>
Reviewed-by: Kevin Laatz <kevin.laatz@intel.com>