[PATCH] Alchemy: Delete unused pt_regs * argument from au1xxx_dbdma_chan_alloc

The third argument of au1xxx_dbdma_chan_alloc's callback function is not
used anywhere.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>