MIPS: vdso: Compile high resolution parts conditionally

If neither the R4K nor the GIC timer is enabled 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>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.714585315@linutronix.de

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

@@ -199,6 +199,13 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 	return cycle_now;
 }
 
+static inline bool mips_vdso_hres_capable(void)
+{
+	return IS_ENABLED(CONFIG_CSRC_R4K) ||
+	       IS_ENABLED(CONFIG_CLKSRC_MIPS_GIC);
+}
+#define __arch_vdso_hres_capable mips_vdso_hres_capable
+
 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
 {
 	return get_vdso_data();