x86/vdso: Remove unused include

Including hrtimer.h is not required and is probably a historical
leftover. Remove it.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20240701-vdso-cleanup-v1-5-36eb64e7ece2@linutronix.de

arch/x86/include/asm/vdso/vsyscall.h

@@ -4,7 +4,6 @@
 
 #ifndef __ASSEMBLY__
 
-#include <linux/hrtimer.h>
 #include <linux/timekeeper_internal.h>
 #include <vdso/datapage.h>
 #include <asm/vgtod.h>