Blackfin: convert to generic checksum code

The Blackfin port only implemented an optimized version of the
csum_tcpudp_nofold function, so convert everything else to the new
generic code.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/lib/Makefile b/arch/blackfin/lib/Makefile
index 635288f..42c47dc 100644
--- a/arch/blackfin/lib/Makefile
+++ b/arch/blackfin/lib/Makefile
@@ -5,7 +5,7 @@
 lib-y := \
 	ashldi3.o ashrdi3.o lshrdi3.o \
 	muldi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o \
-	checksum.o memcpy.o memset.o memcmp.o memchr.o memmove.o \
+	memcpy.o memset.o memcmp.o memchr.o memmove.o \
 	strcmp.o strcpy.o strncmp.o strncpy.o \
 	umulsi3_highpart.o smulsi3_highpart.o \
 	ins.o outs.o