ide: remove obsoleted "idebus=" kernel parameter

* Remove obsoleted "idebus=" kernel parameter.

* Remove no longer needed ide_system_bus_speed() and system_bus_clock()
  (together with idebus_parameter and system_bus_speed variables).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/cmd64x.c b/drivers/ide/pci/cmd64x.c
index 0867471..ca4774a 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -69,7 +69,7 @@
 static void program_cycle_times (ide_drive_t *drive, int cycle_time, int active_time)
 {
 	struct pci_dev *dev = to_pci_dev(drive->hwif->dev);
-	int clock_time = 1000 / (ide_pci_clk ? ide_pci_clk : system_bus_clock());
+	int clock_time = 1000 / (ide_pci_clk ? ide_pci_clk : 33);
 	u8  cycle_count, active_count, recovery_count, drwtim;
 	static const u8 recovery_values[] =
 		{15, 15, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 0};
@@ -128,7 +128,7 @@
 			    ide_pio_timings[pio].active_time);
 
 	setup_count = quantize_timing(ide_pio_timings[pio].setup_time,
-			1000 / (ide_pci_clk ? ide_pci_clk : system_bus_clock()));
+			1000 / (ide_pci_clk ? ide_pci_clk : 33));
 
 	/*
 	 * The primary channel has individual address setup timing registers