m68k: set ARCH_KMALLOC_MINALIGN

Architectures that handle DMA-non-coherent memory need to set
ARCH_KMALLOC_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe: the
buffer doesn't share a cache with the others.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/include/asm/cache.h

@@ -8,4 +8,6 @@
 #define        L1_CACHE_SHIFT  4
 #define        L1_CACHE_BYTES  (1<< L1_CACHE_SHIFT)
 
+#define ARCH_KMALLOC_MINALIGN	L1_CACHE_BYTES
+
 #endif