Add riscv64 to ExclusiveArch

Signed-off-by: David Abdurachmanov <davidlt@rivosinc.com>

box64.spec

@@ -9,7 +9,7 @@ systems, like ARM (host system needs to be 64-bit little-endian).}
 
 Name:           box64
 Version:        0.2.4
-Release:        %autorelease
+Release:        %autorelease -e 0.riscv64
 Summary:        Linux userspace x86_64 emulator with a twist, targeted at ARM64
 
 License:        MIT
@@ -22,7 +22,7 @@ BuildRequires:  make
 BuildRequires:  systemd-rpm-macros
 
 # box64 only supports these architectures
-ExclusiveArch:  aarch64 ppc64le x86_64
+ExclusiveArch:  aarch64 ppc64le x86_64 riscv64
 
 Requires:       %{name}-data = %{version}-%{release}
 %ifarch aarch64