drm/i195: spell out reverse on for_each macros

Do like it's done for list.h macros, and use "reverse" suffix rather
than "rev".

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181114011509.3667-3-lucas.demarchi@intel.com