powerpc: Use generic checksum code in little endian

We need to fix some endian issues in our checksum code. For now
just enable the generic checksum routines for little endian builds.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 38f3b7e..2c69c43 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -139,6 +139,9 @@
 	select OLD_SIGACTION if PPC32
 	select HAVE_DEBUG_STACKOVERFLOW
 
+config GENERIC_CSUM
+	def_bool CPU_LITTLE_ENDIAN
+
 config EARLY_PRINTK
 	bool
 	default y