linux-phytec-ti

NTB: ntb_hw_epf: Decode error command status

ntb_epf_send_command() only checks if COMMAND_STATUS_OK is set or
not. However the endpoint can also set an error if the command failed.
Add a new status bit for command error and decode error in commands
status here.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>