Corrected a bug in the stdvga code where it did not
properly handle 32 bit operations.
The buf_ioreq_t can now store 32 bits of data.
Because this increases its size to 8 bytes,
only 510 elements fit in the buffered_iopage
(down from 672 elements).

Signed-off-by: Robert Phillips <rphillips@virtualiron.com>
Signed-off-by: Ben Guthro <bguthro@virtualiron.com>