riscv: Wire up memfd_secret in UAPI header

Move the __ARCH_WANT_MEMFD_SECRET define added in commit 7bb7f2ac
("arch, mm: wire up memfd_secret system call where relevant") to
<uapi/asm/unistd.h> so __NR_memfd_secret is defined when including
<unistd.h> in userspace.

This allows the memfd_secret selftest to pass on riscv.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Link: https://lore.kernel.org/r/20220505081815.22808-1-tklauser@distanz.ch
Fixes: 7bb7f2ac ("arch, mm: wire up memfd_secret system call where relevant")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/include/asm/unistd.h

@@ -9,7 +9,6 @@
  */
 
 #define __ARCH_WANT_SYS_CLONE
-#define __ARCH_WANT_MEMFD_SECRET
 
 #ifdef CONFIG_COMPAT
 #define __ARCH_WANT_COMPAT_TRUNCATE64

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

@@ -21,6 +21,7 @@
 #endif /* __LP64__ */
 
 #define __ARCH_WANT_SYS_CLONE3
+#define __ARCH_WANT_MEMFD_SECRET
 
 #include <asm-generic/unistd.h>