loongarch: convert to generic syscall table

The uapi/asm/unistd_64.h and asm/syscall_table_64.h headers can now be
generated from scripts/syscall.tbl, which makes this consistent with
the other architectures that have their own syscall.tbl.

Unlike the other architectures using the asm-generic header, loongarch
uses none of the deprecated system calls at the moment.

Both the user visible side of asm/unistd.h and the internal syscall
table in the kernel should have the same effective contents after this.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/loongarch/include/asm/Kbuild

 # SPDX-License-Identifier: GPL-2.0
+syscall-y += syscall_table_64.h
 generated-y += orc_hash.h
 
 generic-y += mcs_spinlock.h

arch/loongarch/include/asm/unistd.h

@@ -8,4 +8,6 @@
 
 #include <uapi/asm/unistd.h>
 
+#define __ARCH_WANT_SYS_CLONE
+
 #define NR_syscalls (__NR_syscalls)

arch/loongarch/include/uapi/asm/Kbuild

 # SPDX-License-Identifier: GPL-2.0
+syscall-y += unistd_64.h
+
 generic-y += kvm_para.h

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

 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#define __ARCH_WANT_SYS_CLONE
 
-#include <asm-generic/unistd.h>
+#include <asm/unistd_64.h>

arch/loongarch/kernel/Makefile.syscalls

+# SPDX-License-Identifier: GPL-2.0
+
+# No special ABIs on loongarch so far
+syscall_abis_64 +=

arch/loongarch/kernel/syscall.c

@@ -20,6 +20,7 @@
 
 #undef __SYSCALL
 #define __SYSCALL(nr, call)	[nr] = (call),
+#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
 
 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long,
 		prot, unsigned long, flags, unsigned long, fd, unsigned long, offset)
@@ -32,7 +33,7 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len, unsigned long,
 
 void *sys_call_table[__NR_syscalls] = {
 	[0 ... __NR_syscalls - 1] = sys_ni_syscall,
-#include <asm/unistd.h>
+#include <asm/syscall_table_64.h>
 };
 
 typedef long (*sys_call_fn)(unsigned long, unsigned long,