usb: chipidea: clarify Documentation/ABI text

Fix grammar and improve readability of chipidea-usb2 text.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Chen <peter.chen@kernel.org>
Cc: linux-usb@vger.kernel.org
Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220827203217.7837-1-rdunlap@infradead.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-platform-chipidea-usb2

@@ -2,8 +2,8 @@ What:		/sys/bus/platform/devices/ci_hdrc.0/role
 Date:		Mar 2017
 Contact:	Peter Chen <peter.chen@nxp.com>
 Description:
-		It returns string "gadget" or "host" when read it, it indicates
-		current controller role.
+		When read, it returns string "gadget" or "host", indicating
+		the current controller role.
 
-		It will do role switch when write "gadget" or "host" to it.
+		It will do role switch when "gadget" or "host" is written to it.
 		Only controller at dual-role configuration supports writing.