usb: phy: phy-ab8500-usb: fix spello of "function"

Fix typo/spello of "function".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: linux-usb@vger.kernel.org
Cc: Jiri Kosina <trivial@kernel.org>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/phy/phy-ab8500-usb.c

@@ -518,7 +518,7 @@ static int ab8500_usb_link_status_update(struct ab8500_usb *ab,
  *   3. Enable AB regulators
  *   4. Enable USB phy
  *   5. Reset the musb controller
- *   6. Switch the ULPI GPIO pins to fucntion mode
+ *   6. Switch the ULPI GPIO pins to function mode
  *   7. Enable the musb Peripheral5 clock
  *   8. Restore MUSB context
  */