powerpc: 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 <labbott@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/powerpc/kernel/vdso32/note.S

@@ -5,6 +5,7 @@
 
 #include <linux/uts.h>
 #include <linux/version.h>
+#include <linux/build-salt.h>
 
 #define ASM_ELF_NOTE_BEGIN(name, flags, vendor, type)			      \
 	.section name, flags;						      \
@@ -23,3 +24,5 @@
 	ASM_ELF_NOTE_BEGIN(".note.kernel-version", "a", UTS_SYSNAME, 0)
 	.long LINUX_VERSION_CODE
 	ASM_ELF_NOTE_END
+
+BUILD_SALT