ARM: vdso: Compile high resolution parts conditionally

If the architected timer is disabled in the kernel configuration then let
the core VDSO code drop the high resolution parts at compile time.
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/20200207124402.622587341@linutronix.de

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

@@ -106,6 +106,12 @@ static __always_inline int clock_getres32_fallback(
 	return ret;
 }
 
+static inline bool arm_vdso_hres_capable(void)
+{
+	return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
+}
+#define __arch_vdso_hres_capable arm_vdso_hres_capable
+
 static __always_inline u64 __arch_get_hw_counter(int clock_mode)
 {
 #ifdef CONFIG_ARM_ARCH_TIMER