ARM: v6k: DMA_CACHE_RWFO isn't appropriate for non-v6k CPUs

Limit DMA_CACHE_RWFO to only v6k SMP CPUs - V6 CPUs aren't SMP capable,
so the read/write for ownership work-around doesn't apply to them.
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/Kconfig

@@ -775,7 +775,7 @@ config NEEDS_SYSCALL_FOR_CMPXCHG
 
 config DMA_CACHE_RWFO
 	bool "Enable read/write for ownership DMA cache maintenance"
-	depends on (CPU_V6 || CPU_V6K) && SMP
+	depends on CPU_V6K && SMP
 	default y
 	help
 	  The Snoop Control Unit on ARM11MPCore does not detect the