[ARM] pxa: Make CPU_XSCALE depend on PXA25x or PXA27x

PXA3 SoCs are supported by the Xscale3 CPU code rather than the
Xscale CPU code.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/Kconfig

@@ -322,7 +322,7 @@ config CPU_SA1100
 # XScale
 config CPU_XSCALE
 	bool
-	depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_PXA || ARCH_IXP4XX || ARCH_IXP2000
+	depends on ARCH_IOP32X || ARCH_IOP33X || PXA25x || PXA27x || ARCH_IXP4XX || ARCH_IXP2000
 	default y
 	select CPU_32v5
 	select CPU_ABRT_EV5T