arm64: compat: select CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION

Commit c1d7e01d7877 ("ipc: use Kconfig options for
__ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION") replaced the
__ARCH_WANT_COMPAT_IPC_PARSE_VERSION token with a corresponding Kconfig
option instead.

This patch updates arm64 to use the latter, rather than #define an
unused token.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index ef54a59..15ac18a 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1,6 +1,7 @@
 config ARM64
 	def_bool y
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_HARDIRQS_NO_DEPRECATED
 	select GENERIC_IOMAP
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 63f853f..68aff28 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -14,7 +14,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #ifdef CONFIG_COMPAT
-#define __ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 #define __ARCH_WANT_COMPAT_STAT64
 #define __ARCH_WANT_SYS_GETHOSTNAME
 #define __ARCH_WANT_SYS_PAUSE