staging: tidspbridge: remove unused code to handle iva_img

There is no way to specify the value of iva_img and since this code
is not being used, remove it.

This analysis resulted from a report by
Chen Gang <gang.chen@asianux.com>, mentioning that the existing code
was wrongly specifying the size to be copied.

Signed-off-by: Omar Ramirez Luna <omar.ramirez@copitl.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>