powerpc/5200: Enable CPU_FTR_NEED_COHERENT for MPC52xx

BestComm, a DMA engine in MPC52xx SoC, requires snooping when
CPU caches are enabled to work properly.

Adding CPU_FTR_NEED_COHERENT fixes NFS problems on MPC52xx machines
introduced by 'powerpc/mm: Fix handling of _PAGE_COHERENT in BAT setup
code' (sha1: 4c456a67).
Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

arch/powerpc/include/asm/cputable.h

@@ -241,9 +241,11 @@ extern const char *powerpc_base_platform;
 /* We need to mark all pages as being coherent if we're SMP or we have a
  * 74[45]x and an MPC107 host bridge. Also 83xx and PowerQUICC II
  * require it for PCI "streaming/prefetch" to work properly.
+ * This is also required by 52xx family.
  */
 #if defined(CONFIG_SMP) || defined(CONFIG_MPC10X_BRIDGE) \
-	|| defined(CONFIG_PPC_83xx) || defined(CONFIG_8260)
+	|| defined(CONFIG_PPC_83xx) || defined(CONFIG_8260) \
+	|| defined(CONFIG_PPC_MPC52xx)
 #define CPU_FTR_COMMON                  CPU_FTR_NEED_COHERENT
 #else
 #define CPU_FTR_COMMON                  0