greybus: camera-gb: Remove hardcode for CSI TX number of lanes

The number of CSI TX lanes is hardcoded to 4. Removing
this and start using value from configure stream response.

NOTE: The patch depends on the CSI init change:
"Use GB CSI params to init camera sub-devs"

Signed-off-by: Evgeniy Borisov <eborisov@mm-sol.com>
Reviewed-by: Gjorgji Rosikopulos <grosikopulos@mm-sol.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>