igc: Remove convert_art_ns_to_tsc()

The core code now provides a mechanism to convert the ART base clock to the
corresponding TSC value without requiring an architecture specific
function.

Replace the direct conversion by filling in the required data.

No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240513103813.5666-5-lakshmi.sowjanya.d@intel.com

drivers/net/ethernet/intel/igc/igc_ptp.c

@@ -938,7 +938,11 @@ static bool igc_is_crosststamp_supported(struct igc_adapter *adapter)
 static struct system_counterval_t igc_device_tstamp_to_system(u64 tstamp)
 {
 #if IS_ENABLED(CONFIG_X86_TSC) && !defined(CONFIG_UML)
-	return convert_art_ns_to_tsc(tstamp);
+	return (struct system_counterval_t) {
+		.cs_id		= CSID_X86_ART,
+		.cycles		= tstamp,
+		.use_nsecs	= true,
+	};
 #else
 	return (struct system_counterval_t) { };
 #endif