s390: remove 31 bit support

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e58 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/bitops.h

@@ -51,32 +51,6 @@
 
 #define __BITOPS_NO_BARRIER	"\n"
 
-#ifndef CONFIG_64BIT
-
-#define __BITOPS_OR		"or"
-#define __BITOPS_AND		"nr"
-#define __BITOPS_XOR		"xr"
-#define __BITOPS_BARRIER	"\n"
-
-#define __BITOPS_LOOP(__addr, __val, __op_string, __barrier)	\
-({								\
-	unsigned long __old, __new;				\
-								\
-	typecheck(unsigned long *, (__addr));			\
-	asm volatile(						\
-		"	l	%0,%2\n"			\
-		"0:	lr	%1,%0\n"			\
-		__op_string "	%1,%3\n"			\
-		"	cs	%0,%1,%2\n"			\
-		"	jl	0b"				\
-		: "=&d" (__old), "=&d" (__new), "+Q" (*(__addr))\
-		: "d" (__val)					\
-		: "cc", "memory");				\
-	__old;							\
-})
-
-#else /* CONFIG_64BIT */
-
 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 
 #define __BITOPS_OR		"laog"
@@ -125,8 +99,6 @@
 
 #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
 
-#endif /* CONFIG_64BIT */
-
 #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
 
 static inline unsigned long *