vdso/helpers: Explicitly include vdso/processor.h

The usage of cpu_relax() requires vdso/processor.h. Currently
this header is included transitively, but that transitive inclusion is
about to go away.

Explicitly include the header.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260227-vdso-header-cleanups-v2-11-35d60acf7410@linutronix.de

include/vdso/helpers.h

@@ -6,6 +6,7 @@
 
 #include <asm/barrier.h>
 #include <vdso/datapage.h>
+#include <vdso/processor.h>
 #include <vdso/clocksource.h>
 
 static __always_inline bool vdso_is_timens_clock(const struct vdso_clock *vc)