usb: Fixed a few typos

Fixed typos in comments of various drivers/usb files

Signed-off-by: Mickael Maison <mickael.maison@gmail.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 487abcf..56a0661 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1272,7 +1272,7 @@
  * The usb core itself is however optimized for host controllers that can dma
  * using regular system memory - like pci devices doing bus mastering.
  *
- * To support host controllers with limited dma capabilites we provide dma
+ * To support host controllers with limited dma capabilities we provide dma
  * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
  * For this to work properly the host controller code must first use the
  * function dma_declare_coherent_memory() to point out which memory area