doc: fix a few typos

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Documentation/usb/dwc3.txt

@@ -28,7 +28,7 @@ Please pick something while reading :)
       none
 
     - primary handler of the EP-interrupt
-      reads the event and tries to process it. Everything that requries
+      reads the event and tries to process it. Everything that requires
       sleeping is handed over to the Thread. The event is saved in an
       per-endpoint data-structure.
       We probably have to pay attention not to process events once we

Documentation/usb/wusb-cbaf

@@ -36,7 +36,7 @@ COMMAND/ARGS are
 
  get-cdid DEVICE
 
-   Get the device ID associated to the HOST-CHDI we sent with
+   Get the device ID associated to the HOST-CHID we sent with
    'set-chid'. We might not know about it.
 
  set-cc DEVICE

Documentation/video4linux/README.cpia2

@@ -12,7 +12,7 @@ gqcam application to view this stream.
 	The driver is implemented as two kernel modules. The cpia2 module
 contains the camera functions and the V4L interface.  The cpia2_usb module
 contains usb specific functions.  The main reason for this was the size of the
-module was getting out of hand, so I separted them.  It is not likely that
+module was getting out of hand, so I separated them.  It is not likely that
 there will be a parallel port version.
 
 FEATURES: