m68k: Add __NR_syscalls along with NR_syscalls

NR_syscalls macro holds the number of system call
exist in m68k architecture. We have to change the
value of NR_syscalls, if we add or delete a system
call.

One of the patch in this patch series has a script
which will generate a uapi header based on syscall-
.tbl file. The syscall.tbl file contains the total
number of system calls information. So we have two
option to update NR_syscalls value.

1. Update NR_syscalls in asm/unistd.h manually by
   counting the no.of system calls. No need to up-
   date NR_syscalls until we either add a new sys-
   tem call or delete existing system call.

2. We can keep this feature it above mentioned sc-
   ript, that will count the number of syscalls and
   keep it in a generated file. In this case we
   don't need to explicitly update NR_syscalls in
   asm/unistd.h file.

The 2nd option will be the recommended one. For that,
I added the __NR_syscalls macro in uapi/asm/unistd.h
along with NR_syscalls asm/unistd.h. The macro __NR-
_syscalls also added for making the name convention
same across all architecture. While __NR_syscalls
isn't strictly part of the uapi, having it as part
of the generated header to simplifies the implement-
ation. We also need to enclose this macro with #ifdef
__KERNEL__ to avoid side effects.
Signed-off-by: NFiroz Khan <firoz.khan@linaro.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/include/asm/unistd.h

@@ -4,8 +4,7 @@
 
 #include <uapi/asm/unistd.h>
 
-
-#define NR_syscalls		380
+#define NR_syscalls	__NR_syscalls
 
 #define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR

arch/m68k/include/uapi/asm/unistd.h

@@ -387,4 +387,8 @@
 #define __NR_pwritev2		378
 #define __NR_statx		379
 
+#ifdef __KERNEL__
+#define __NR_syscalls		380
+#endif
+
 #endif /* _UAPI_ASM_M68K_UNISTD_H_ */