Move the linker script from cloudabi64/ to cloudabi/.

It turns out that it works perfectly fine for generating 32-bits vDSOs
as well. While there, get rid of the extraneous .s file extension.

sys/compat/cloudabi/cloudabi_vdso.lds

@@ -1,5 +1,5 @@
 /*
- * Linker script for 64-bit vDSO for CloudABI.
+ * Linker script for the vDSO for CloudABI.
  * Based on sys/amd64/linux/linux_vdso.lds.s
  *
  * $FreeBSD$

sys/conf/files.amd64

@@ -10,7 +10,7 @@
 #
 cloudabi64_vdso.o		optional	compat_cloudabi64	\
 	dependency	"$S/contrib/cloudabi/cloudabi_vdso_x86_64.S"	\
-	compile-with	"${CC} -x assembler-with-cpp -shared -nostdinc -nostdlib -Wl,-T$S/compat/cloudabi64/cloudabi64_vdso.lds.s $S/contrib/cloudabi/cloudabi_vdso_x86_64.S -o ${.TARGET}" \
+	compile-with	"${CC} -x assembler-with-cpp -shared -nostdinc -nostdlib -Wl,-T$S/compat/cloudabi/cloudabi_vdso.lds $S/contrib/cloudabi/cloudabi_vdso_x86_64.S -o ${.TARGET}" \
 	no-obj no-implicit-rule						\
 	clean		"cloudabi64_vdso.o"
 #

sys/conf/files.arm64

@@ -1,7 +1,7 @@
 # $FreeBSD$
 cloudabi64_vdso.o		optional	compat_cloudabi64	\
 	dependency	"$S/contrib/cloudabi/cloudabi_vdso_aarch64.S"	\
-	compile-with	"${CC} -x assembler-with-cpp -shared -nostdinc -nostdlib -Wl,-T$S/compat/cloudabi64/cloudabi64_vdso.lds.s $S/contrib/cloudabi/cloudabi_vdso_aarch64.S -o ${.TARGET}" \
+	compile-with	"${CC} -x assembler-with-cpp -shared -nostdinc -nostdlib -Wl,-T$S/compat/cloudabi/cloudabi_vdso.lds $S/contrib/cloudabi/cloudabi_vdso_aarch64.S -o ${.TARGET}" \
 	no-obj no-implicit-rule						\
 	clean		"cloudabi64_vdso.o"
 #

sys/modules/cloudabi64/Makefile

@@ -25,7 +25,7 @@ BINARY_ARCHITECTURE=i386
 
 cloudabi64_vdso.o: ${VDSO_SRCS}
 	${CC} -x assembler-with-cpp -shared -nostdinc -nostdlib \
-	    -Wl,-T${SYSDIR}/compat/cloudabi64/cloudabi64_vdso.lds.s \
+	    -Wl,-T${SYSDIR}/compat/cloudabi/cloudabi_vdso.lds \
 	    ${VDSO_SRCS} -o ${.TARGET}
 
 cloudabi64_vdso_blob.o: cloudabi64_vdso.o