via-ircc: Pass PCI device pointer to dma_{alloc, free}_coherent()

via-ircc has been passing a NULL pointer to DMA allocation functions,
which is completely invalid and results in a BUG on PowerPC.  Now
that we always have the device pointer available, pass it in.

Reference: http://bugs.debian.org/619450


Reported-by: Andrew Buckeridge <andrewb@bgc.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Andrew Buckeridge <andrewb@bgc.com.au> [against 2.6.32]
Signed-off-by: David S. Miller <davem@davemloft.net>