y2038: utimes: Rework #ifdef guards for compat syscalls

After changing over to 64-bit time_t syscalls, many architectures will
want compat_sys_utimensat() but not respective handlers for utime(),
utimes() and futimesat(). This adds a new __ARCH_WANT_SYS_UTIME32 to
complement __ARCH_WANT_SYS_UTIME. For now, all 64-bit architectures that
support CONFIG_COMPAT set it, but future 64-bit architectures will not
(tile would not have needed it either, but got removed).

As older 32-bit architectures get converted to using CONFIG_64BIT_TIME,
they will have to use __ARCH_WANT_SYS_UTIME32 instead of
__ARCH_WANT_SYS_UTIME. Architectures using the generic syscall ABI don't
need either of them as they never had a utime syscall.

Since the compat_utimbuf structure is now required outside of
CONFIG_COMPAT, I'm moving it into compat_time.h.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
changed from last version:
- renamed __ARCH_WANT_COMPAT_SYS_UTIME to __ARCH_WANT_SYS_UTIME32

arch/parisc/include/asm/unistd.h

@@ -152,6 +152,7 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5)	\
 #define __ARCH_WANT_COMPAT_SYS_TIME
 #define __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL
 #define __ARCH_WANT_SYS_UTIME
+#define __ARCH_WANT_SYS_UTIME32
 #define __ARCH_WANT_SYS_WAITPID
 #define __ARCH_WANT_SYS_SOCKETCALL
 #define __ARCH_WANT_SYS_FADVISE64