asm-generic: siginfo: define ia64 si_codes unconditionally

Unlike system call numbers the assignment of si_codes has never had a
reason to be made per architecture.  Some architectures have had unique
conditions to report and reporting those conditions needed new si_codes.
Nothing has ever needed si_codes to have different values on different
architectures.  The si_code space is vast so even with defining all
si_codes on all architectures there is no danger in running out of
si_code values.

The history of the si_codes BUS_MCEERR_AR, BUS_MCEER_AO, SEGV_BNDERR,
and SEGV_PKUERR show that a need of one architecture frequently becomes
a need of another architecture which makes sharing si_codes between
architectures a positive benefit and something to be encouraged.

Where there are no conflicts with the historical ia64 arch specific
si_codes and any other si_codes make them generic si_codes.  We might
need them on another architecture someday.

This leaves only the good example of arch generic si_codes in the kernel
for future architectures and architecture enhancments to follow.
Without bad examples to follow it should be easy to avoid the mistakes
of the past.

Reported-by: Eric W. Biederman <ebiederm@xmission.com>
[arnd: took Eric's changelog text]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

include/uapi/asm-generic/siginfo.h

@@ -186,11 +186,9 @@ typedef struct siginfo {
 #define ILL_PRVREG	6	/* privileged register */
 #define ILL_COPROC	7	/* coprocessor error */
 #define ILL_BADSTK	8	/* internal stack error */
-#ifdef __ia64__
-# define ILL_BADIADDR	9	/* unimplemented instruction address */
-# define __ILL_BREAK	10	/* illegal break */
-# define __ILL_BNDMOD	11	/* bundle-update (modification) in progress */
-#endif
+#define ILL_BADIADDR	9	/* unimplemented instruction address */
+#define __ILL_BREAK	10	/* illegal break */
+#define __ILL_BNDMOD	11	/* bundle-update (modification) in progress */
 #define NSIGILL		11
 
 /*
@@ -204,13 +202,11 @@ typedef struct siginfo {
 #define FPE_FLTRES	6	/* floating point inexact result */
 #define FPE_FLTINV	7	/* floating point invalid operation */
 #define FPE_FLTSUB	8	/* subscript out of range */
-#ifdef __ia64__
-# define __FPE_DECOVF	9	/* decimal overflow */
-# define __FPE_DECDIV	10	/* decimal division by zero */
-# define __FPE_DECERR	11	/* packed decimal error */
-# define __FPE_INVASC	12	/* invalid ASCII digit */
-# define __FPE_INVDEC	13	/* invalid decimal digit */
-#endif
+#define __FPE_DECOVF	9	/* decimal overflow */
+#define __FPE_DECDIV	10	/* decimal division by zero */
+#define __FPE_DECERR	11	/* packed decimal error */
+#define __FPE_INVASC	12	/* invalid ASCII digit */
+#define __FPE_INVDEC	13	/* invalid decimal digit */
 #define NSIGFPE		13
 
 /*