ARM: vdso: Remove unused function

The function is nowhere used. Aside of that this check should only cover
the high resolution parts of the VDSO which require a VDSO capable
clocksource and not the complete functionality as the name suggests. Will
be replaced with something more useful.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.438179009@linutronix.de

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

@@ -49,13 +49,6 @@ int __arm_get_clock_mode(struct timekeeper *tk)
 }
 #define __arch_get_clock_mode __arm_get_clock_mode
 
-static __always_inline
-int __arm_use_vsyscall(struct vdso_data *vdata)
-{
-	return vdata[CS_HRES_COARSE].clock_mode;
-}
-#define __arch_use_vsyscall __arm_use_vsyscall
-
 static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {