ide: move ide_rate_filter() calls to the upper layer (take 2)

* Move ide_rate_filter() calls from host drivers to IDE core.

* Make ide_rate_filter() static.

* Make 'speed' argument of ->speedproc const.

v2:
* Fix it8213_tune_chipset() comment.

There should be no functionality changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/triflex.c b/drivers/ide/pci/triflex.c
index 098692a..47cf89b 100644
--- a/drivers/ide/pci/triflex.c
+++ b/drivers/ide/pci/triflex.c
@@ -40,7 +40,7 @@
 #include <linux/ide.h>
 #include <linux/init.h>
 
-static int triflex_tune_chipset(ide_drive_t *drive, u8 xferspeed)
+static int triflex_tune_chipset(ide_drive_t *drive, const u8 speed)
 {
 	ide_hwif_t *hwif = HWIF(drive);
 	struct pci_dev *dev = hwif->pci_dev;
@@ -48,7 +48,6 @@
 	u16 timing = 0;
 	u32 triflex_timings = 0;
 	u8 unit = (drive->select.b.unit & 0x01);
-	u8 speed = ide_rate_filter(drive, xferspeed);
 	
 	pci_read_config_dword(dev, channel_offset, &triflex_timings);