MIPS: TX49xx: Define ARCH_KMALLOC_MINALIGN

With SLAB, it works without ARCH_KMALLOC_MINALIGN, but with SLOB/SLUB,
ARCH_KMALLOC_MINALIGN is required to ensure alignment of kmalloced
buffer.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1248/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>