MIPS: Octeon: remove duplicated include from dma-octeon.c

MIPS: Octeon: remove duplicated include from dma-octeon.c

Remove duplicated include.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: <linux-mips@vger.kernel.org>
Cc: <kernel-janitors@vger.kernel.org>