virtiofsd: Enable build for RISC-V

With this change, `virtiofsd` (gnu target) could be built and then to be
used with other components.

Depends: #10741
Fixes: #10739

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

tools/packaging/scripts/lib.sh

@@ -67,6 +67,7 @@ arch_to_golang()
 	case "$arch" in
 		aarch64) echo "arm64";;
 		ppc64le) echo "$arch";;
+		riscv64) echo "$arch";;
 		x86_64) echo "amd64";;
 		s390x) echo "s390x";;
 		*) die "unsupported architecture: $arch";;
@@ -200,6 +201,9 @@ get_virtiofsd_image_name() {
 	        "ppc64le")
 	                libc="gnu"
 	                ;;
+	        "riscv64")
+	                libc="gnu"
+	                ;;
 	        "s390x")
 	                libc="gnu"
 	                ;;