MIPS: JZ4740: Fix the JZ4740_IRQ_DMA macro

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3459/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>