asm-generic: introduce asm/bitsperlong.h

This provides a reliable way for asm-generic/types.h and other
files to find out if it is running on a 32 or 64 bit platform.

We cannot use CONFIG_64BIT for this in headers that are included
from user space because CONFIG symbols are not available there.
We also cannot do it inside of asm/types.h because some headers
need the word size but cannot include types.h.

The solution is to introduce a new header <asm/bitsperlong.h>
that defines both __BITS_PER_LONG for user space and
BITS_PER_LONG for usage in the kernel. The asm-generic
version falls back to 32 bit unless the architecture overrides
it, which I did for all 64 bit platforms.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/include/asm-generic/Kbuild.asm b/include/asm-generic/Kbuild.asm
index 70d1855..290910e 100644
--- a/include/asm-generic/Kbuild.asm
+++ b/include/asm-generic/Kbuild.asm
@@ -9,6 +9,7 @@
 endif
 unifdef-y += auxvec.h
 unifdef-y += byteorder.h
+unifdef-y += bitsperlong.h
 unifdef-y += errno.h
 unifdef-y += fcntl.h
 unifdef-y += ioctl.h