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/legacy/ali14xx.c b/drivers/ide/legacy/ali14xx.c
index 90c65cf..052125f 100644
--- a/drivers/ide/legacy/ali14xx.c
+++ b/drivers/ide/legacy/ali14xx.c
@@ -116,7 +116,7 @@
 	int time1, time2;
 	u8 param1, param2, param3, param4;
 	unsigned long flags;
-	int bus_speed = ide_vlb_clk ? ide_vlb_clk : system_bus_clock();
+	int bus_speed = ide_vlb_clk ? ide_vlb_clk : 50;
 
 	/* calculate timing, according to PIO mode */
 	time1 = ide_pio_cycle_time(drive, pio);
diff --git a/drivers/ide/legacy/ht6560b.c b/drivers/ide/legacy/ht6560b.c
index 4fe516d..dd6dfb3 100644
--- a/drivers/ide/legacy/ht6560b.c
+++ b/drivers/ide/legacy/ht6560b.c
@@ -212,7 +212,7 @@
 {
 	int active_time, recovery_time;
 	int active_cycles, recovery_cycles;
-	int bus_speed = ide_vlb_clk ? ide_vlb_clk : system_bus_clock();
+	int bus_speed = ide_vlb_clk ? ide_vlb_clk : 50;
 
         if (pio) {
 		unsigned int cycle_time;
diff --git a/drivers/ide/legacy/qd65xx.c b/drivers/ide/legacy/qd65xx.c
index 6424af1..51dba82 100644
--- a/drivers/ide/legacy/qd65xx.c
+++ b/drivers/ide/legacy/qd65xx.c
@@ -110,7 +110,7 @@
 
 static u8 qd6500_compute_timing (ide_hwif_t *hwif, int active_time, int recovery_time)
 {
-	int clk = ide_vlb_clk ? ide_vlb_clk : system_bus_clock();
+	int clk = ide_vlb_clk ? ide_vlb_clk : 50;
 	u8 act_cyc, rec_cyc;
 
 	if (clk <= 33) {
@@ -132,7 +132,7 @@
 
 static u8 qd6580_compute_timing (int active_time, int recovery_time)
 {
-	int clk = ide_vlb_clk ? ide_vlb_clk : system_bus_clock();
+	int clk = ide_vlb_clk ? ide_vlb_clk : 50;
 	u8 act_cyc, rec_cyc;
 
 	act_cyc = 17 - IDE_IN(active_time   * clk / 1000 + 1, 2, 17);