[PATCHv5 4/4] arm64: Add build salt to the vDSO

The vDSO needs to have a unique build id in a similar manner
to the kernel and modules. Use the build salt macro.

Signed-off-by: Laura Abbott <redacted>
---
v5: I was previously focused on x86 only but since powerpc gave a patch,
I figured I would do arm64 since the changes were also fairly simple.
---
 arch/arm64/kernel/vdso/note.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/vdso/note.S b/arch/arm64/kernel/vdso/note.S
index b82c85e5d972..2c429dfd3f45 100644
--- a/arch/arm64/kernel/vdso/note.S
+++ b/arch/arm64/kernel/vdso/note.S

@@ -22,7 +22,10 @@
 #include <linux/uts.h>
 #include <linux/version.h>
 #include <linux/elfnote.h>
+#include <linux/build-salt.h>

 ELFNOTE_START(Linux, 0, "a")
        .long LINUX_VERSION_CODE
 ELFNOTE_END
+
+BUILD_SALT;