byteorder: provide swabb.h generically in asm/byteorder.h

This is needed during the transition to the new byteorder headers as the
swabb.h functionality will be provided from asm/byteorder.h in the new
version.  To avoid breakage on arches still using the old implementation,
provide swabb.h from asm/byteorder.h as well.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/byteorder/Kbuild

 unifdef-y += big_endian.h
 unifdef-y += little_endian.h
 unifdef-y += swab.h
+unifdef-y += swabb.h

include/linux/byteorder/big_endian.h

@@ -10,6 +10,7 @@
 
 #include <linux/types.h>
 #include <linux/byteorder/swab.h>
+#include <linux/byteorder/swabb.h>
 
 #define __constant_htonl(x) ((__force __be32)(__u32)(x))
 #define __constant_ntohl(x) ((__force __u32)(__be32)(x))

include/linux/byteorder/little_endian.h

@@ -10,6 +10,7 @@
 
 #include <linux/types.h>
 #include <linux/byteorder/swab.h>
+#include <linux/byteorder/swabb.h>
 
 #define __constant_htonl(x) ((__force __be32)___constant_swab32((x)))
 #define __constant_ntohl(x) ___constant_swab32((__force __be32)(x))