staging: vchi: Use enum vchiq_bulk_mode instead of vchi's transmission flags

vchi has a set of transfer flags which almost map 1:1 to vchiq's own
transfer modes. For the sake of simplicity let's use the later and
delete vchi's.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20200629150945.10720-20-nsaenzjulienne@suse.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>