Fix misspellings of "system", "controller", "interrupt" and "necessary".

Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
diff --git a/drivers/ata/pata_it821x.c b/drivers/ata/pata_it821x.c
index 988ef73..ca9aae0 100644
--- a/drivers/ata/pata_it821x.c
+++ b/drivers/ata/pata_it821x.c
@@ -105,7 +105,7 @@
 
 /*
  *	We allow users to force the card into non raid mode without
- *	flashing the alternative BIOS. This is also neccessary right now
+ *	flashing the alternative BIOS. This is also necessary right now
  *	for embedded platforms that cannot run a PC BIOS but are using this
  *	device.
  */
@@ -383,7 +383,7 @@
  *	@ap: ATA port
  *	@device: Device number (not pointer)
  *
- *	Device selection hook. If neccessary perform clock switching
+ *	Device selection hook. If necessary perform clock switching
  */
 
 static void it821x_passthru_dev_select(struct ata_port *ap,