drivers:misc: ti-st: firmware download optimization

To fasten the process of firmware download, the chip allows
disabling of the command complete event generation from host.
In these cases, only few very essential commands would have
the command complete events and hence the wait associated with
them.

So now the driver would wait for a command complete event, only
when it comes across a wait event during firmware parsing.
This would also mean we need to skip not just the change baud
rate command but also the wait for it.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>