dt-bindings: usb: musb: Grammar s/the/to/, s/is/are/

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRob Herring <robh@kernel.org>

Documentation/devicetree/bindings/usb/am33xx-usb.txt

@@ -4,9 +4,9 @@
 - reg: offset and length of the usbss register sets
 - ti,hwmods : must be "usb_otg_hs"
 
-The glue layer contains multiple child nodes. It is required the have
+The glue layer contains multiple child nodes. It is required to have
 at least a control module node, USB node and a PHY node. The second USB
-node and its PHY node is optional. The DMA node is also optional.
+node and its PHY node are optional. The DMA node is also optional.
 
 Reset module
 ~~~~~~~~~~~~